roll in the hay vs copulation

roll in the hay and copulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
roll in the hay	Yes	No	Yes	No
copulation	Yes	No	No	No

As nouns, copulation is a hypernym of roll in the hay; that is, copulation is a word with a broader meaning than roll in the hay:

roll in the hay: slang for sexual intercourse
copulation: sexual activity between individuals, especially the insertion of a man's penis into a woman's vagina until orgasm and ejaculation occur

roll in the hay (noun)	copulation (noun)
slang for sexual intercourse	sexual activity between individuals, especially the insertion of a man's penis into a woman's vagina until orgasm and ejaculation occur

roll in the hay (verb)	copulation (verb)
have sexual intercourse with