long distance vs long-distance call

long distance and long-distance call both are nouns.

Word	Noun	Adjective	Verb	Adverb
long distance	Yes	No	No	No
long-distance call	Yes	No	No	No

As nouns, long distance and long-distance call are synonyms defined as:

long distance and long-distance call: a telephone call made outside the local calling area

Other synonyms of long distance include trunk call.

long distance (noun)	long-distance call (noun)
a telephone call made outside the local calling area	a telephone call made outside the local calling area