spoilsport vs wet blanket

spoilsport and wet blanket both are nouns.

Word	Noun	Adjective	Verb	Adverb
spoilsport	Yes	No	No	No
wet blanket	Yes	No	No	No

As nouns, spoilsport and wet blanket are synonyms defined as:

Other synonyms of spoilsport include killjoy, party pooper.

spoilsport (noun)	wet blanket (noun)
someone who spoils the pleasure of others	someone who spoils the pleasure of others