long distance vs trunk call

long distance and trunk call both are nouns.

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

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

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

Other synonyms of long distance include long-distance call.

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