skirt vs close in

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

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

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

Other hyponyms of skirt include fringe, gird, girdle, cloister, enclose, inclose, shut in, hem in, cloister.

skirt (noun)	close in (noun)
a garment hanging from the waist; worn mainly by girls and women
cloth covering that forms the part of a garment below the waist
informal terms for a (young) woman
(Fungi) a remnant of the partial veil that in mature mushrooms surrounds the stem like a collar

skirt (verb)	close in (verb)
avoid or try to avoid fulfilling, answering, or performing (duties, questions, or issues)	surround completely
extend on all sides of simultaneously; encircle	advance or converge on
pass around or about; move along the border
form the edge of