bottleneck vs obstruct

bottleneck is a noun but obstruct is not a noun.

Word	Noun	Adjective	Verb	Adverb
bottleneck	Yes	No	Yes	No
obstruct	No	No	Yes	No

As verbs, obstruct is a hypernym of bottleneck; that is, obstruct is a word with a broader meaning than bottleneck:

Other hypernyms of bottleneck include block, blockade, embarrass, hinder, stymie, stymy.

bottleneck (noun)	obstruct (noun)
the narrow part of a bottle near the top
a narrowing that reduces the flow through a channel

bottleneck (verb)	obstruct (verb)
become narrow, like a bottleneck	block passage through
slow down or impede by creating an obstruction	shut out from view or get in the way so as to hide from sight
	hinder or prevent the progress or accomplishment of