close off vs blockade

close off is not a noun while blockade is a noun.

Word	Noun	Adjective	Verb	Adverb
close off	No	No	Yes	No
blockade	Yes	No	Yes	No

As verbs, blockade is a hypernym of close off; that is, blockade is a word with a broader meaning than close off:

Other hypernyms of close off include bar, barricade, block, block off, block up, stop.

close off (noun)	blockade (noun)
	a war measure that isolates some area of importance to the enemy
	prevents access or progress

close off (verb)	blockade (verb)
block off the passage through	impose a blockade on
isolate or separate	obstruct access to
stem the flow of	render unsuitable for passage
	hinder or prevent the progress or accomplishment of