/ Thesaurus / A Synonyms of atomic number 65 Find synonyms for: Noun1. terbium, Tb, atomic number 65, metallic element, metalusage: a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbiteWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language