spoilsport

[ spoil-spawrt, -spohrt ]
/ ˈspɔɪlˌspɔrt, -ˌspoʊrt /

noun

a person whose selfish or unsportsmanlike attitudes or actions spoil the pleasure of others, as in a game or social gathering.

Origin of spoilsport

First recorded in 1815–25; from phrase spoil the sport
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for spoilsport

British Dictionary definitions for spoilsport

spoilsport
/ (ˈspɔɪlˌspɔːt) /

noun

informal a person who spoils the pleasure of other people by his actions or attitudes
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012