insert vs close in

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

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

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

Other hypernyms of insert include enclose, inclose, shut in.

insert (noun)	close in (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

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