Boo-boo/ˈbuːˌbuː/nounA mistake or error.(by or to young children) A minor injury, such as a cut or a bruise.(by or to young children) Feces.verb(by or to young children) To defecate.Synonyms: blooper, blunder, faux pas, fluff, gaffe, lapse, slip, stumble🔗 Explore synonyms & relationships🌍 See word origin & history