Yes, HEADGEARS is a Scrabble word!

Letter values in Scrabble US: H 4, E 1, A 1, D 2, G 2, E 1, A 1, R 1, S 1.

Is it a valid word?

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

clothing for the head
the hoist at the pithead of a mine
stable gear consisting of any part of a harness that fits about the horse's head