marten cat vs black cat

marten cat and black cat both are nouns.

Word	Noun	Adjective	Verb	Adverb
marten cat	Yes	No	No	No
black cat	Yes	No	No	No

As nouns, black cat is a hyponym of marten cat; that is, black cat is a word with a more specific, narrower meaning than marten cat:

marten cat: agile slender-bodied arboreal mustelids somewhat larger than weasels
black cat: large dark brown North American arboreal carnivorous mammal

marten cat (noun)	black cat (noun)
agile slender-bodied arboreal mustelids somewhat larger than weasels	large dark brown North American arboreal carnivorous mammal