Bad Sport, Someone Who Does Not Take Defeat Well
Puzzle 4 of All Things Ice Cream Easy Pack
Question is: Bad Sport, Someone Who Does Not Take Defeat Well
and the answer is: SORELOSER
Word Meaning:
SORE LOSER — (informal, derogatory) One who complains or blames others for one's loss; one who is easily angered by losing a game or contest, or because of some other misfortune or bad luck.
Definitions from Wiktionary.