long-distance call vs long distance

long-distance call and long distance both are nouns.

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

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

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

Other synonyms of long-distance call include trunk call.

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