Yes, ARABESQUE is a Scrabble word!

Letter values in Scrabble US: A 1, R 1, A 1, B 3, E 1, S 1, Q 10, U 1, E 1.

Is it a valid word?

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

position in which the dancer has one leg raised behind and arms outstretched in a conventional pose
an ornament that interlaces simulated foliage in an intricate design