compartment vs call box

compartment and call box both are nouns.

Word	Noun	Adjective	Verb	Adverb
compartment	Yes	No	No	No
call box	Yes	No	No	No

As nouns, call box is a hyponym of compartment; that is, call box is a word with a more specific, narrower meaning than compartment:

compartment: a space into which an area is subdivided
call box: a numbered compartment in a post office where mail is put to be called for

Other hyponyms of compartment include cell, cubbyhole, pigeonhole, letter box, PO Box, POB, Post-Office box.

compartment (noun)	call box (noun)
a partitioned section, chamber, or separate room within a larger enclosed area	booth for using a telephone
a space into which an area is subdivided	a numbered compartment in a post office where mail is put to be called for