close in vs insert

close in is not a noun while insert is a noun.

Word	Noun	Adjective	Verb	Adverb
close in	No	No	Yes	No
insert	Yes	No	Yes	No

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

close in (noun)	insert (noun)
	(film) a still picture that is introduced and that interrupts the action of a film
	(broadcasting) a local announcement inserted into a network program
	an artifact that is inserted or is to be inserted
	a folded section placed between the leaves of another publication

close in (verb)	insert (verb)
surround completely	place, fit, or thrust (something) into another thing
advance or converge on	insert casually
	put or introduce into something
	fit snugly into