chess vs chess opening

chess and chess opening both are nouns.

Word	Noun	Adjective	Verb	Adverb
chess	Yes	No	No	No
chess opening	Yes	No	No	No

chess (noun)	chess opening (noun)
a board game for two players who move their 16 pieces according to specific rules; the object is to checkmate the opponent's king	a recognized sequence of moves at the beginning of a game of chess
weedy annual native to Europe but widely distributed as a weed especially in wheat