How to Cite a Dictionary or Encyclopedia Entry

Reference works are cited by entry. The main things to settle are who counts as the author and what date to give, and both depend on whether the entry is signed and whether you read it online or in print.

What to Collect

• The entry word or entry title, exactly as the headword appears
• The entry's author, if it is signed (look at the end of the entry)
• The title of the dictionary or encyclopedia, and the edition for print
• Editor, publisher and year, for print and for scholarly encyclopedias
• URL and the date you consulted it, for online entries
• Page number, for print

The main worked example is APA's own model entry, "semantics" in the online Merriam-Webster dictionary. The signed-entry example is Sydney Brandon's entry on the surgeon James Barry in the Oxford Dictionary of National Biography.

Quick Reference by Major Style

APA (7th Edition)

Unsigned online entry, where the publisher acts as a group author:

In-text: (Merriam-Webster, n.d.)

Print entry:

In the print example the publisher is not repeated, because it is the same as the author.

Signed entry in an online encyclopedia that archives each edition:

In-text: (Graham, 2019). The Stanford Encyclopedia archives each edition, so the archived URL is used and no retrieval date is needed.

MLA (9th Edition)

In-text: ("Semantics")

Print:

MLA includes the part of speech, and an entry number when the word has more than one entry, so the reader knows which definition you mean. The print example is the MLA Style Center's own. To point to a particular sense, the Style Center adds the definition number in the in-text citation: ("Content," def. 4.1.b).

Chicago (18th Edition)

The Chicago Manual's rules for dictionaries and encyclopedias are in sections 14.130 to 14.132, which sit behind the manual's subscription. The free Citation Quick Guide covers website content, and an online dictionary entry fits that pattern: the entry title in quotation marks, the site and its owner, a posted or revision date (or an access date when the page shows none), and the URL.

Footnote, adapted from the Quick Guide's web page pattern:

Cite the entry word, not a volume or page number. If your department follows an earlier edition of the manual or has its own Chicago guide, check the form it expects for reference works.

Signed entries in specialist reference works are cited under the entry's author, like a chapter in an edited book:

Harvard (Cite Them Right)

Unsigned online entry:

In-text: ('Canadian Shield', 2020)

Signed entry:

In-text: (Brandon, 2008)

Both examples follow University College Dublin Library's Harvard guide, which is based on Cite Them Right. When an online entry shows no year, use (no date).

IEEE

The IEEE Reference Guide has no dictionary format. Adapt the website format for online entries and the book-chapter format for print:

In-text: [1]

In engineering and computing, a term is better defined from a standard. IEEE and ISO publish vocabularies for this purpose, and a standard has its own reference format in the IEEE guide.

Signed or Unsigned?

This decides who goes first.

• Unsigned entries (general dictionaries, most of Britannica's short entries): APA starts with the publisher as a group author. MLA and Harvard start with the entry title. A Chicago note starts with the entry title.
• Signed entries (the Stanford Encyclopedia of Philosophy, the Oxford Dictionary of National Biography, Oxford Research Encyclopedias, many Britannica long-form articles): every style starts with the entry's author, and the entry is handled like a chapter in an edited book.

Look for a name at the very end of the entry, or under the title. Britannica often credits "The Editors of Encyclopaedia Britannica", and that credit can stand as a group author.

The Oxford English Dictionary

The OED is a special case because it is a historical dictionary, with dated quotations and revision notes for each entry. MLA's Style Center cites it like this:

MLA's in-text citation for that entry names the sense: ("Heavy," def. A.18). The OED has since moved its entries to new addresses, so copy the URL your browser shows. The OED's website also offers a "Cite" button on each entry, which supplies the revision date. Most students reach the OED through a library subscription. Use the public oed.com address in the citation, not your library's proxy link.

Do You Need the Definition?

Opening an essay with "The dictionary defines X as ..." rarely earns its place. A general dictionary records everyday usage. Academic writing usually needs the way a term is used in the field, and that comes from the scholarly literature. Reserve dictionary citations for cases where ordinary meaning, etymology or a change in usage is the point you are making.

Common Mistakes

• Citing the whole dictionary when you used one entry
• Leaving out the retrieval or access date for an online entry that has no date
• Listing the editor-in-chief as the author of an unsigned entry
• Missing the author's name at the end of a signed entry and citing it as anonymous
• Citing Dictionary.com or Google's definition box without checking where the definition comes from. Google says its English dictionary is provided by Oxford Languages; cite a dictionary you can link to directly.

Sources for These Formats

• APA Style, "Dictionary Entry References" (apastyle.apa.org). APA publishes no encyclopedia-entry page; the Stanford Encyclopedia of Philosophy entry above was checked against the archived Summer 2019 edition at plato.stanford.edu and follows APA's chapter-in-an-edited-book pattern.
• MLA Style Center, "How do I cite a term in an online or print dictionary that lists several numbered definitions?" and "When citing a print dictionary in MLA style, do I include a page number?" (style.mla.org)
• The Chicago Manual of Style, 18th ed., Citation Quick Guide, "Web page"; the manual's rules for reference works are in sections 14.130 to 14.132 (chicagomanualofstyle.org)
• Pears and Shields, Cite Them Right; University College Dublin Library, Harvard style guide, "Encyclopedias and dictionaries"
• IEEE Reference Guide, version 3.28.2025, sections B, P and T

Full style rules: APA, MLA, Chicago, Harvard, IEEE.