/ Dictionary / Index S swim fin: Meaning and Definition of Find definitions for: swim' fin" Pronunciation: [key] one of a pair of flippers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. swim bladder swim mask Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language