Yes, ESCALATOR is a Scrabble word!

Letter values in Scrabble US: E 1, S 1, C 3, A 1, L 1, A 1, T 1, O 1, R 1.

Is it a valid word?

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

a clause in a contract that provides for an increase or a decrease in wages or prices or benefits etc. depending on certain conditions (as a change in the cost of living index)
a stairway whose steps move continuously on a circulating belt

Also: escalator clause, moving staircase, moving stairway.