/ Dictionary / Index U ultrafiltrate: Meaning and Definition of Find definitions for: ul•tra•fil•trate Pronunciation: (ul"tru-fil'trāt), [key] — n. Physical Chem. a liquid that has been passed through an ultrafilter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ultrafilter ultrahigh Related Content Daily Word Quiz: reticent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language