/ Dictionary / Index T transactinide: Meaning and Definition of Find definitions for: trans•ac•ti•nide Pronunciation: (trans-ak'tu-nīd", tranz-), [key] — adj. Chem. noting or pertaining to elements having higher atomic weights than those of the actinide series. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: transactinide (Thesaurus) transact transaction Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language