forelimb vs foreleg

forelimb and foreleg both are nouns.

Word	Noun	Adjective	Verb	Adverb
forelimb	Yes	No	No	No
foreleg	Yes	No	No	No

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

forelimb: the front limb (or the homologous structure in other animals, such as a flipper or wing)
foreleg: the forelimb of a quadruped

forelimb (noun)	foreleg (noun)
the front limb (or the homologous structure in other animals, such as a flipper or wing)	the forelimb of a quadruped