brachial artery vs artery

brachial artery and artery both are nouns.

Word	Noun	Adjective	Verb	Adverb
brachial artery	Yes	No	No	No
artery	Yes	No	No	No

As nouns, artery is a hypernym of brachial artery; that is, artery is a word with a broader meaning than brachial artery:

brachial artery: the main artery of the upper arm; a continuation of the axillary artery; bifurcates into the radial and ulnar arteries at the elbow
artery: a blood vessel that carries blood from the heart to the body

Other hypernyms of brachial artery include arteria, arterial blood vessel.

brachial artery (noun)	artery (noun)
the main artery of the upper arm; a continuation of the axillary artery; bifurcates into the radial and ulnar arteries at the elbow	a major thoroughfare that bears important traffic
	a blood vessel that carries blood from the heart to the body