Yes, DEMURRERS is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, M 3, U 1, R 1, R 1, E 1, R 1, S 1.

Is it a valid word?

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

(law) a formal objection to an opponent's pleadings
(law) any pleading that attacks the legal sufficiency of the opponent's pleadings
a defendant's answer or plea denying the truth of the charges against him