/ Thesaurus / S Synonyms of space cadet Find synonyms for: Noun1. space cadet, simpleton, simpleusage: someone who seems unable to respond appropriately to reality (as if under the influence of some narcotic drug)WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: illegible Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language