true cat vs felid

true cat and felid both are nouns.

Word	Noun	Adjective	Verb	Adverb
true cat	Yes	No	No	No
felid	Yes	No	No	No

As nouns, felid is a hypernym of true cat; that is, felid is a word with a broader meaning than true cat:

true cat: feline mammal usually having thick soft fur and no ability to roar: domestic cats; wildcats
felid: any of various lithe-bodied roundheaded fissiped mammals, many with retractile claws

Other hypernyms of true cat include feline.

true cat (noun)	felid (noun)
feline mammal usually having thick soft fur and no ability to roar: domestic cats; wildcats	any of various lithe-bodied roundheaded fissiped mammals, many with retractile claws