Yes, LIQUIDATOR is a Scrabble word!

Letter values in Scrabble US: L 1, I 1, Q 10, U 1, I 1, D 2, A 1, T 1, O 1, R 1.

Is it a valid word?

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

a criminal who commits homicide (who performs the unlawful premeditated killing of another human being)
(law) a person (usually appointed by a court of law) who liquidates assets or preserves them for the benefit of affected parties