1. All the words of a language.
2. The sum of words used by, understood by, or at the command of a particular person or group.
3. A list of words and often phrases, usually arranged alphabetically and defined or translated; a lexicon or glossary.
4. A supply of expressive means; a repertoire of communication: a dancer's vocabulary of movement.

[French vocabulaire, from Old French, from Medieval Latin vocābulārium, from neuter of vocābulārius, of words, from Latin vocābulum, name. See vocable.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.