decision maker vs administrator

decision maker and administrator both are nouns.

Word	Noun	Adjective	Verb	Adverb
decision maker	Yes	No	No	No
administrator	Yes	No	No	No

As nouns, decision maker and administrator are synonyms defined as:

decision maker (noun)	administrator (noun)
someone who administers a business	someone who administers a business
	the party appointed by a probate court to distribute the estate of someone who dies without a will or without naming an executor
	someone who manages a government agency or department