sit-down vs sit-down strike

sit-down and sit-down strike both are nouns.

Word	Noun	Adjective	Verb	Adverb
sit-down	Yes	No	No	No
sit-down strike	Yes	No	No	No

As nouns, sit-down and sit-down strike are synonyms defined as:

sit-down and sit-down strike: a strike in which workers refuse to leave the workplace until a settlement is reached

sit-down (noun)	sit-down strike (noun)
a strike in which workers refuse to leave the workplace until a settlement is reached	a strike in which workers refuse to leave the workplace until a settlement is reached