smoke hole vs blowhole

smoke hole and blowhole both are nouns.

Word	Noun	Adjective	Verb	Adverb
smoke hole	Yes	No	No	No
blowhole	Yes	No	No	No

As nouns, blowhole is a hypernym of smoke hole; that is, blowhole is a word with a broader meaning than smoke hole:

Other hypernyms of smoke hole include vent-hole, vent, venthole.

smoke hole (noun)	blowhole (noun)
a vent (as in a roof) for smoke to escape	a hole for the escape of gas or air
	the spiracle of a cetacean located far back on the skull