/ Dictionary / Index U ultramicrochemistry: Meaning and Definition of Find definitions for: ul•tra•mi•cro•chem•is•try Pronunciation: (ul"tru-mī"krō-kem'u-strē), [key] — n. the branch of microchemistry dealing with minute quantities of material weighing one microgram or less. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ultramicrobalance ultramicrofiche 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