Breadcrumb Home > Thesaurus > P Synonyms of protoactinium Find synonyms for: Noun 1. protactinium, protoactinium, Pa, atomic number 91, metallic element, metal usage: a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of protoactinium (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: turgid Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language