infix vs penetrate

infix is a noun but penetrate is not a noun.

Word	Noun	Adjective	Verb	Adverb
infix	Yes	No	Yes	No
penetrate	No	No	Yes	No

As verbs, penetrate is a hyponym of infix; that is, penetrate is a word with a more specific, narrower meaning than infix:

infix (noun)	penetrate (noun)
an affix that is inserted inside the word

infix (verb)	penetrate (verb)
attach a morpheme into a stem word	come to understand
put or introduce into something	become clear or enter one's consciousness or emotions
	pass into or through, often by overcoming resistance
	insert the penis into the vagina or anus of
	spread or diffuse through
	make one's way deeper into or through
	enter a group or organization in order to spy on the members