foot soldier vs cog

foot soldier and cog both are nouns.

Word	Noun	Adjective	Verb	Adverb
foot soldier	Yes	No	No	No
cog	Yes	No	Yes	No

As nouns, cog is a hyponym of foot soldier; that is, cog is a word with a more specific, narrower meaning than foot soldier:

Other hyponyms of foot soldier include associate, bottom dog, man, second banana, second fiddle.

foot soldier (noun)	cog (noun)
fights on foot with small arms	tooth on the rim of gear wheel
an assistant subject to the authority or control of another	a subordinate who performs an important but routine function

foot soldier (verb)	cog (verb)
	join pieces of wood with cogs
	roll steel ingots