/ Thesaurus / C Synonyms of clyde william tombaugh Find synonyms for: Noun1. Tombaugh, Clyde Tombaugh, Clyde William Tombaughusage: United States astronomer who discovered the planet Pluto (1906-1997)WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: devout Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language