Yes, BIASSES is a Scrabble word!

Letter values in Scrabble US: B 3, I 1, A 1, S 1, S 1, E 1, S 1.

Is it a valid word?

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

a partiality that prevents objective consideration of an issue or situation
a line or cut across a fabric that is not at right angles to a side of the fabric