call in vs call-in

call in is not a noun while call-in is a noun.

Word	Noun	Adjective	Verb	Adverb
call in	No	No	Yes	No
call-in	Yes	No	No	No

call in (noun)	call-in (noun)
	a telephone call to a radio station or a television station in which the caller participates in the on-going program

call in (verb)	call-in (verb)
make a phone call
summon to a particular activity or employment
summon to enter
cause to be returned
demand payment of (a loan)
pay a brief visit
take a player out of a game in order to exchange for another player