backroom boy vs advisor

backroom boy and advisor both are nouns.

Word	Noun	Adjective	Verb	Adverb
backroom boy	Yes	No	No	No
advisor	Yes	No	No	No

As nouns, advisor is a hypernym of backroom boy; that is, advisor is a word with a broader meaning than backroom boy:

backroom boy: an expert adviser involved in making important decisions but usually lacking official status
advisor: an expert who gives advice

Other hypernyms of backroom boy include adviser, consultant.

backroom boy (noun)	advisor (noun)
an expert adviser involved in making important decisions but usually lacking official status	an expert who gives advice