poilu vs soldier

poilu and soldier both are nouns.

Word	Noun	Adjective	Verb	Adverb
poilu	Yes	No	No	No
soldier	Yes	No	Yes	No

As nouns, soldier is a hypernym of poilu; that is, soldier is a word with a broader meaning than poilu:

poilu (noun)	soldier (noun)
thick stew made of rice and chicken and small game; southern U.S.	a wingless sterile ant or termite having a large head and powerful jaws adapted for defending the colony
a French soldier (especially in World War I)	an enlisted man or woman who serves in an army

poilu (verb)	soldier (verb)
	serve as a soldier in the military