Yes, SUNNAHS is a Scrabble word!

Letter values in Scrabble US: S 1, U 1, N 1, N 1, A 1, H 4, S 1.

Is it a valid word?

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

(Islam) the way of life prescribed as normative for Muslims on the basis of the teachings and practices of Muhammad and interpretations of the Koran