Yes, UNITARDS is a Scrabble word!

Letter values in Scrabble US: U 1, N 1, I 1, T 1, A 1, R 1, D 2, S 1.

Is it a valid word?

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

a tight-fitting garment of stretchy material that covers the body from the shoulders to the thighs (and may have long sleeves or legs reaching down to the ankles); worn by ballet dancers and acrobats for practice or performance

Also: body suit, cat suit.