Is “Killjoy” a Scrabble word?
Yes
KILLJOY
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Killjoy
/ˈkɪlˌdʒɔɪ/
noun
1.A person who is anti-fun, or prevents others from having fun.
Synonyms: buzzkill, dampener, miserabilist, party pooper, spoilsport