oopsy /ˈuːpsi/noun 1verb 1exclamation 1forms 3 noun1 •A mistake; often when babies and young children soil their pants.I have made an oopsy. verb1 •To make a mistake, particularly (of a baby) to soil its pants.I think your baby might have oopsied. exclamation1 •(informal) Synonym of oops."Oopsy..." She grabbed the wheel and made a quick recovery. "Sorry." — 1992 formsoopsied · oopsying · oopsies