infiltrate vs get together

infiltrate is not a noun while get together is a noun.

Word	Noun	Adjective	Verb	Adverb
infiltrate	No	No	Yes	No
get together	Yes	No	Yes	No

As verbs, get together is a hypernym of infiltrate; that is, get together is a word with a broader meaning than infiltrate:

Other hypernyms of infiltrate include fall in, join.

infiltrate (noun)	get together (noun)
	a small informal social gathering

infiltrate (verb)	get together (verb)
pass through an enemy line; in a military conflict	get together socially or for a specific purpose
cause (a liquid) to enter by penetrating the interstices	become part of; become a member of a group or organization
pass into or through by filtering or permeating	get people together
enter a group or organization in order to spy on the members