extensor muscle vs quad

extensor muscle and quad both are nouns.

Word	Noun	Adjective	Verb	Adverb
extensor muscle	Yes	No	No	No
quad	Yes	No	No	No

As nouns, quad is a hyponym of extensor muscle; that is, quad is a word with a more specific, narrower meaning than extensor muscle:

extensor muscle: a skeletal muscle whose contraction extends or stretches a body part
quad: a muscle of the thigh that extends the leg

Other hyponyms of extensor muscle include musculus quadriceps femoris, quadriceps, quadriceps femoris.

extensor muscle (noun)	quad (noun)
a skeletal muscle whose contraction extends or stretches a body part	a rectangular area surrounded on all sides by buildings
	(printing) a block of type without a raised letter; used for spacing between words or sentences
	a muscle of the thigh that extends the leg
	one of four children born at the same time from the same pregnancy