longtime vs long-time

longtime and long-time both are adjectives.

Word	Noun	Adjective	Verb	Adverb
longtime	No	Yes	No	No
long-time	No	Yes	No	No

As adjectives, longtime and long-time are synonyms defined as:

longtime and long-time: having existed or persisted or continued in a particular role or state for a long time

longtime (adjective)	long-time (adjective)
having existed or persisted or continued in a particular role or state for a long time	having existed or persisted or continued in a particular role or state for a long time