/ Dictionary / Index F femtometer: Meaning and Definition of Find definitions for: fem•to•me•ter Pronunciation: (fem'tu-mē"tur), [key] — n. Physics. fermi. Symbol: fm Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: femtometer (Thesaurus) femto- femur 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