/ Dictionary / Index F function key: Meaning and Definition of Find definitions for: func'tion key" Pronunciation: [key] a key on a computer terminal or microcomputer keyboard that, when pressed, causes a specific computational or mechanical operation to be carried out. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. functionary function space Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language