roll in the hay vs shag

roll in the hay and shag both are nouns.

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

As nouns, roll in the hay and shag are synonyms defined as:

Other synonyms of roll in the hay include ass, fuck, fucking, nookie, nooky, piece of ass, piece of tail, screw, screwing, shtup.

roll in the hay (noun)	shag (noun)
slang for sexual intercourse	a lively dance step consisting of hopping on each foot in turn
	slang for sexual intercourse
	a fabric with long coarse nap
	a matted tangle of hair or fiber
	a strong coarse tobacco that has been shredded

roll in the hay (verb)	shag (verb)
have sexual intercourse with	dance the shag