filter vs infiltrate

filter is a noun but infiltrate is not a noun.

Word	Noun	Adjective	Verb	Adverb
filter	Yes	No	Yes	No
infiltrate	No	No	Yes	No

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

filter (noun)	infiltrate (noun)
device that removes something from whatever passes through it
an electrical device that alters the frequency spectrum of signals passing through it

filter (verb)	infiltrate (verb)
remove by passing through a filter	pass through an enemy line; in a military conflict
pass through	cause (a liquid) to enter by penetrating the interstices
run or flow slowly, as in drops or in an unsteady stream	pass into or through by filtering or permeating
	enter a group or organization in order to spy on the members