Yes, ADJUNCTS is a Scrabble word!

Letter values in Scrabble US: A 1, D 2, J 8, U 1, N 1, C 3, T 1, S 1.

Is it a valid word?

ADJUNCTS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

something added to another thing but not an essential part of it
a person who is an assistant or subordinate to another
a construction that can be used to extend the meaning of a word or phrase but is not one of the main constituents of a sentence