Dictionaries are considered a special type of reference in Chicago style -- requiring citation in just the footnotes of the text, not in the bibliography. There are a couple ways to write a dictionary citation, depending on whether the entry is from a traditional dictionary, a CD-ROM or online. Both citation methods require identifying information such as the dictionary title, edition number and entry name.
Citing a Traditional Dictionary
For a traditional dictionary, include the dictionary name in italics, edition number if it is not the first edition, the abbreviation "s.v." (which means "sub verdo") and entry name in the citation. Firstly, include the citation number in superscript at the end of the sentence, after the period, where you reference the entry. For example, "The zebra is a horse-related animal native to Africa.^1" The citation number will differ depending on whether or not you have made any previous citations in the paper. The second part of the citation appears in the footer of the page, indicated with the same number used in the text. For this example, the citation would look like this:
- Collins English Dictionary, 11th ed., s.v. "zebra."
Citing a Dictionary CD-ROM
For a CD-ROM dictionary, include all the same information as in a citation for a traditional dictionary, as well as the CD-ROM version number. Place this in parentheses before the entry name. For example, consider the sentence "A fortnight is an Old English word that means two weeks.^2" Your citation should look like this:
- Oxford English Dictionary, 2nd ed. (CD-ROM, version 3.0), s.v. “fortnight."
Citing an Online Dictionary
For an online dictionary, include the dictionary name in italics, the abbreviation "s.v.," the entry name, the date the entry was accessed and the full URL in the citation. For example, the citation for the sentence "Blood is a bodily fluid that circulates through the body of all vertebrate animals,^3" should look like this:
- Merriam-Webster, s.v. “blood,” accessed February 5, 2015, http://www.merriam-webster.com/medical/blood.