/ Dictionary / Index U ultramicrotome: Meaning and Definition of Find definitions for: ul•tra•mi•cro•tome Pronunciation: (ul"tru-mī'kru-tōm"), [key] — n. Histol. a microtome capable of producing very fine slices of tissue or cellular specimens for electron microscopic examination. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ultramicroscopy ultraminiature Related Content Daily Word Quiz: ontiguous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language