Breadcrumb Home > Thesaurus > R Synonyms of rb Find synonyms for: Noun 1. rubidium, Rb, atomic number 37, metallic element, metal usage: a soft silvery metallic element of the alkali metal group; burns in air and reacts violently in water; occurs in carnallite and lepidolite and pollucite WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of rb (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: variegate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language