pinaforePronunciation: /ˈpɪnəfɔː/Translate pinafore | into French | into German | into Italian | into Spanish Definition of pinafore noun (also British pinafore dress) a collarless sleeveless dress worn over a blouse or jumper. a woman’s loose sleeveless garment, typically full length and worn over clothes to keep them clean. a sleeveless apron-like garment worn over a young girl’s dress, typically having ties or buttons at the back. Origin: late 18th century: from pin + afore (because the term originally denoted an apron with a bib pinned on the front of a dress)pinafore in other Oxford dictionaries Definition of pinafore in the US English dictionary