grenadier vs infantryman

grenadier and infantryman both are nouns.

Word	Noun	Adjective	Verb	Adverb
grenadier	Yes	No	No	No
infantryman	Yes	No	No	No

As nouns, infantryman is a hypernym of grenadier; that is, infantryman is a word with a broader meaning than grenadier:

Other hypernyms of grenadier include foot soldier, footslogger, marcher.

grenadier (noun)	infantryman (noun)
deep-sea fish with a large head and body and long tapering tail	fights on foot with small arms
an infantryman equipped with grenades