Breadcrumb Home > Thesaurus > S Synonyms of subsonic Find synonyms for: Adjective 1. subsonic (vs. supersonic) (vs. sonic) usage: (of speed) less than that of sound in a designated medium; "aircraft flying at subsonic speeds" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of subsonic (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: rococo Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language