gyrus vs frontal gyrus

gyrus and frontal gyrus both are nouns.

Word	Noun	Adjective	Verb	Adverb
gyrus	Yes	No	No	No
frontal gyrus	Yes	No	No	No

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

gyrus: a convex fold or elevation in the surface of the brain
frontal gyrus: any of the convolutions of the outer surface of the frontal lobe of the cerebrum

Other hyponyms of gyrus include temporal gyrus, parietal gyrus, occipital gyrus, central gyrus.

gyrus (noun)	frontal gyrus (noun)
a convex fold or elevation in the surface of the brain	any of the convolutions of the outer surface of the frontal lobe of the cerebrum