utilizer vs user

utilizer and user both are nouns.

Word	Noun	Adjective	Verb	Adverb
utilizer	Yes	No	No	No
user	Yes	No	No	No

As nouns, user is a hypernym of utilizer; that is, user is a word with a broader meaning than utilizer:

utilizer: someone who puts to good use
user: a person who makes use of a thing; someone who uses or employs something

utilizer (noun)	user (noun)
someone who puts to good use	a person who makes use of a thing; someone who uses or employs something
	a person who uses something or someone selfishly or unethically
	a person who takes drugs