Video shows what onesie means. A one-piece garment for an infant or small child, generally worn over a diaper.. One-piece adult loungewear jumpsuit.. One-piece fashionable streetwear worn mostly by teenagers.. onesie synonyms: romper, romper suit. Onesie Meaning. How to pronounce, definition audio dictionary. How to say onesie. Powered by MaryTTS, Wiktionary
