Pronunciation (UK) IPA (key): /ˈdjuːbi.əs/ (US) IPA (key): /ˈdu.bi.əs/ Audio (US)(file) Adjective Positive dubious Comparative more dubious Superlative most dubious A dubious decision or opinion is one that you don't believe is honest, safe, or reliable. Synonym: doubtful If you are dubious about something, you are not sure if you should believe or trust it.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads