The word crocodile has a complex etymology (“Crocodile” 139).
Explain
An encyclopedia or a dictionary that has no author is alphabetized in the list of works cited under the word or entry that you consulted—not under the title of the reference work itself.
Either in your text or in your parenthetical reference, mention the word or the entry.
Give a page number on which the entry may be found.
Works cited entry
“Crocodile.” The American Heritage Dictionary of the English Language, 4th ed., 2000.