/ Dictionary / Index A ADF: Meaning and Definition of Find definitions for: ADF Pronunciation: [key] automatic direction finder. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ad extremum* ad fin.* Related Content Daily Word Quiz: confectionery Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language