How to Cite an Encyclopedia or Dictionary in APA, MLA & Chicago Format (2026 Guide)
Learn how to cite encyclopedia and dictionary entries in APA, MLA, and Chicago format with examples. Includes online sources like Wikipedia and Britannica.
How to Cite an Encyclopedia or Dictionary in APA, MLA & Chicago Format (2026 Guide)
Need to cite a dictionary definition or encyclopedia entry in your research paper? You're not alone. Reference works like encyclopedias and dictionaries are common starting points for academic research — but citing them correctly can be tricky.
This guide shows you exactly how to cite encyclopedia and dictionary entries in APA, MLA, and Chicago format, with examples for both print and online sources.
Table of Contents
- When to Cite Encyclopedias and Dictionaries
- APA Format for Encyclopedia and Dictionary Citations
- MLA Format for Encyclopedia and Dictionary Citations
- Chicago Format for Encyclopedia and Dictionary Citations
- How to Cite Wikipedia
- How to Cite Britannica
- How to Cite Merriam-Webster
- FAQ
When to Cite Encyclopedias and Dictionaries
Before diving into formats, let's clarify when you should cite these sources:
Use encyclopedias and dictionaries for:
- Background information on a topic
- Defining key terms
- Getting an overview before deeper research
- Finding dates, facts, or quick reference data
Be cautious:
- Many professors don't consider encyclopedias (especially Wikipedia) as scholarly sources
- Use them for background, not as primary evidence
- Always check your assignment guidelines
Pro tip: Use encyclopedias to understand a topic, then cite the original sources they reference.
APA Format for Encyclopedia and Dictionary Citations
APA 7th edition has specific rules for reference works. Here's how to format them:
Encyclopedia Entry (Print) — APA
Reference list format:
Author, A. A. (Year). Title of entry. In E. E. Editor (Ed.), Title of encyclopedia (edition, Vol. #, pp. xx–xx). Publisher.
Example:
Smith, J. D. (2023). Climate change. In A. B. Johnson (Ed.), Encyclopedia of environmental science (3rd ed., Vol. 2, pp. 145–152). Academic Press.
In-text citation: (Smith, 2023)
Encyclopedia Entry (Online) — APA
Reference list format:
Author, A. A. (Year, Month Day). Title of entry. In E. E. Editor (Ed.), Title of encyclopedia. Publisher. URL
Example:
Green, R. (2024, March 15). Artificial intelligence. In Encyclopedia Britannica. https://www.britannica.com/technology/artificial-intelligence
In-text citation: (Green, 2024)
Dictionary Entry (Online) — APA
Reference list format:
Title of entry. (n.d.). In Dictionary name. Retrieved Month Day, Year, from URL
Example:
Research. (n.d.). In Merriam-Webster dictionary. Retrieved May 6, 2026, from https://www.merriam-webster.com/dictionary/research
In-text citation: ("Research," n.d.)
No Author — APA
When there's no author listed, start with the entry title:
Quantum mechanics. (2024). In Encyclopedia of physics (2nd ed., pp. 789–801). Science Publishers.
In-text citation: ("Quantum Mechanics," 2024)
MLA Format for Encyclopedia and Dictionary Citations
MLA 9th edition uses a flexible "containers" approach. Here's how it works for reference works:
Encyclopedia Entry (Print) — MLA
Works Cited format:
Author Last Name, First Name. "Title of Entry." Title of Encyclopedia, edited by Editor Name, edition, vol. #, Publisher, Year, pp. xx–xx.
Example:
Williams, Sarah. "Renaissance Art." The Oxford Encyclopedia of Art, edited by Michael Brown, 4th ed., vol. 3, Oxford UP, 2023, pp. 234–251.
In-text citation: (Williams 234)
Encyclopedia Entry (Online) — MLA
Works Cited format:
Author Last Name, First Name. "Title of Entry." Title of Encyclopedia, Publisher, Day Month Year, URL.
Example:
Mueller, David. "Black Holes." Encyclopedia Britannica, 12 Feb. 2024, www.britannica.com/science/black-hole.
In-text citation: (Mueller)
Dictionary Entry — MLA
Works Cited format:
"Title of Entry." Dictionary Name, Publisher, URL. Accessed Day Month Year.
Example:
"Epistemology." Merriam-Webster.com Dictionary, Merriam-Webster, www.merriam-webster.com/dictionary/epistemology. Accessed 6 May 2026.
In-text citation: ("Epistemology")
No Author — MLA
Simply start with the entry title in quotation marks:
"Global Warming." World Book Encyclopedia, vol. 8, World Book, 2024, pp. 156–162.
In-text citation: ("Global Warming" 156)
Chicago Format for Encyclopedia and Dictionary Citations
Chicago style offers two systems: Notes-Bibliography (common in humanities) and Author-Date (common in sciences). Here's both:
Encyclopedia Entry — Notes-Bibliography
Footnote format:
First Name Last Name, "Title of Entry," in Title of Encyclopedia, ed. Editor Name (Place: Publisher, Year), page numbers.
Example footnote:
1. Robert Chen, "Cognitive Psychology," in The Encyclopedia of Psychology, ed. Alan Howard (New York: Psychology Press, 2023), 112–118.
Bibliography entry:
Chen, Robert. "Cognitive Psychology." In The Encyclopedia of Psychology, edited by Alan Howard, 112–118. New York: Psychology Press, 2023.
Encyclopedia Entry — Author-Date
Reference list format:
Last Name, First Name. Year. "Title of Entry." In Title of Encyclopedia, edited by Editor Name, page numbers. Place: Publisher.
Example:
Chen, Robert. 2023. "Cognitive Psychology." In The Encyclopedia of Psychology, edited by Alan Howard, 112–118. New York: Psychology Press.
In-text citation: (Chen 2023, 115)
Dictionary Entry — Chicago
Most dictionary entries are cited in footnotes only, not the bibliography:
Footnote:
1. Merriam-Webster, s.v. "paradigm," accessed May 6, 2026, https://www.merriam-webster.com/dictionary/paradigm.
Note: "s.v." stands for sub verbo (Latin for "under the word").
How to Cite Wikipedia
Wikipedia is a special case. Here's how to cite it properly in all three formats:
Wikipedia — APA
Article title. (Year, Month Day). In Wikipedia. URL
Example:
Machine learning. (2026, April 28). In Wikipedia. https://en.wikipedia.org/wiki/Machine_learning
Tip: Use the "Cite this page" link on Wikipedia to get the permanent URL for the version you're citing.
Wikipedia — MLA
"Article Title." Wikipedia, Wikimedia Foundation, Day Month Year, URL.
Example:
"Machine Learning." Wikipedia, Wikimedia Foundation, 28 Apr. 2026, en.wikipedia.org/wiki/Machine_learning.
Wikipedia — Chicago
Footnote:
1. Wikipedia, s.v. "Machine learning," last modified April 28, 2026, https://en.wikipedia.org/wiki/Machine_learning.
Important: Many instructors don't accept Wikipedia citations. Use Wikipedia to find better sources, then cite those instead.
How to Cite Britannica
Encyclopedia Britannica is a respected source. Here's the format:
Britannica — APA
Author, A. A. (Year, Month Day). Title of article. In Encyclopedia Britannica. URL
Example:
Lovelace, P. (2024, February 10). Renewable energy. In Encyclopedia Britannica. https://www.britannica.com/science/renewable-energy
If no author is listed:
Renewable energy. (2024, February 10). In Encyclopedia Britannica. https://www.britannica.com/science/renewable-energy
Britannica — MLA
Author Last Name, First Name. "Article Title." Encyclopedia Britannica, Day Month Year, URL.
Example:
Lovelace, Patricia. "Renewable Energy." Encyclopedia Britannica, 10 Feb. 2024, www.britannica.com/science/renewable-energy.
Britannica — Chicago
Footnote:
1. Patricia Lovelace, "Renewable Energy," Encyclopedia Britannica, February 10, 2024, https://www.britannica.com/science/renewable-energy.
How to Cite Merriam-Webster
Merriam-Webster is the go-to dictionary for academic writing:
Merriam-Webster — APA
Word. (n.d.). In Merriam-Webster dictionary. Retrieved Month Day, Year, from URL
Example:
Synthesis. (n.d.). In Merriam-Webster dictionary. Retrieved May 6, 2026, from https://www.merriam-webster.com/dictionary/synthesis
Merriam-Webster — MLA
"Word." Merriam-Webster.com Dictionary, Merriam-Webster, URL. Accessed Day Month Year.
Example:
"Synthesis." Merriam-Webster.com Dictionary, Merriam-Webster, www.merriam-webster.com/dictionary/synthesis. Accessed 6 May 2026.
Merriam-Webster — Chicago
Footnote:
1. Merriam-Webster, s.v. "synthesis," accessed May 6, 2026, https://www.merriam-webster.com/dictionary/synthesis.
Quick Reference Table
| Source Type | APA | MLA | Chicago | |-------------|-----|-----|----------| | Print encyclopedia | Author. (Year). Entry. In Editor (Ed.), Encyclopedia (ed., Vol., pp.). Publisher. | Author. "Entry." Encyclopedia, ed. Editor, vol., Publisher, Year, pp. | Author, "Entry," in Encyclopedia, ed. Editor (Place: Publisher, Year), pp. | | Online encyclopedia | Author. (Year). Entry. In Encyclopedia. URL | Author. "Entry." Encyclopedia, Date, URL. | Author, "Entry," Encyclopedia, Date, URL. | | Online dictionary | Entry. (n.d.). In Dictionary. Retrieved Date, from URL | "Entry." Dictionary.com, Publisher, URL. Accessed Date. | Dictionary, s.v. "entry," accessed Date, URL. | | Wikipedia | Entry. (Date). In Wikipedia. URL | "Entry." Wikipedia, Foundation, Date, URL. | Wikipedia, s.v. "Entry," modified Date, URL. |
Common Mistakes to Avoid
1. Forgetting the retrieval date for online dictionaries
- APA requires "Retrieved [Date], from URL" for sources that change
2. Not using "s.v." in Chicago
- "s.v." is required before dictionary entries in Chicago style
3. Treating Wikipedia like a scholarly source
- Most professors want primary sources, not encyclopedias
4. Missing the version date for Wikipedia
- Wikipedia changes constantly — cite the specific version you used
5. Incorrect capitalization
- APA: Only capitalize the first word of entry titles
- MLA/Chicago: Use title case
FAQ
Can I cite Wikipedia in my research paper?
Technically yes, but many professors don't accept it. Wikipedia is best used for background research. Find the original sources Wikipedia cites and use those instead.
Do I need to cite a dictionary if I just use one definition?
Yes. Any time you quote, paraphrase, or directly use information from a source, you must cite it — even for a single definition.
What if the encyclopedia entry has no author?
Start your citation with the entry title instead. All three formats (APA, MLA, Chicago) allow for this.
Should I use print or online encyclopedias?
Online sources are generally more current. However, some specialized print encyclopedias contain information not available online. Use whichever best supports your research.
Is Encyclopedia Britannica considered a credible source?
Yes. Britannica is peer-reviewed and written by experts. It's more academically acceptable than Wikipedia, though primary sources are still preferred for most research.
Key Takeaways
- Always check assignment guidelines — some professors don't accept encyclopedia or dictionary citations
- Use specific formats for print vs. online sources
- Include retrieval dates for online dictionaries in APA
- Use "s.v." in Chicago footnotes for dictionary entries
- Cite the version when using Wikipedia
- Use reference works for background, then cite primary sources for your main arguments
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