/ Dictionary / Index A American Expeditionary Forces: Meaning and Definition of Find definitions for: Amer'ican Expedi'tionary Forc"es Pronunciation: [key] troops sent to Europe by the U.S. Army during World War I. Abbr.: A.E.F., AEF Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. American English American Farm Bureau Federation Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language