blockade vs close off

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

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

As verbs, close off is a hyponym of blockade; that is, close off is a word with a more specific, narrower meaning than blockade:

Other hyponyms of blockade include block off, shut off, close.

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

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