Yes, PREDICTOR is a Scrabble word!

Letter values in Scrabble US: P 3, R 1, E 1, D 2, I 1, C 3, T 1, O 1, R 1.

Is it a valid word?

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

someone who makes predictions of the future (usually on the basis of special knowledge)
information that supports a probabilistic estimate of future events
a computer for controlling antiaircraft fire that computes the position of an aircraft at the instant of a shell's arrival