cutter vs gem cutter

cutter and gem cutter both are nouns.

Word	Noun	Adjective	Verb	Adverb
cutter	Yes	No	No	No
gem cutter	Yes	No	No	No

As nouns, gem cutter is a hyponym of cutter; that is, gem cutter is a word with a more specific, narrower meaning than cutter:

Other hyponyms of cutter include garment cutter, glass-cutter, glass cutter.

cutter (noun)	gem cutter (noun)
a cutting implement; a tool for cutting	one who cuts and shapes precious stones
a boat for communication between ship and shore
a sailing vessel with a single mast set further back than the mast of a sloop
someone whose work is cutting (as e.g. cutting cloth for garments)
someone who carves the meat
someone who cuts or carves stone