spoilsport UK /ˈspɔɪl.spɔːt/US /ˈspɔɪl.spɔɹt/adjective 1noun 1forms 3 adjective1 •Like a spoilsport.It may seem somewhat spoilsport to focus in on this negative after another important victory but to ignore it would be delusion. Southgate will not be letting it escape his attention. — 2019 noun1 •Someone who puts an end to others' fun, especially harmless fun.I know I am a sad spoilsport, but it would make me wretched. — 1908 formsspoilsports · more spoilsport · most spoilsport