Yes, EMPIRES is a Scrabble word!

Letter values in Scrabble US: E 1, M 3, P 3, I 1, R 1, E 1, S 1.

Is it a valid word?

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

the domain ruled by an emperor or empress; the region over which imperial dominion is exercised
a group of countries under a single authority
a monarchy with an emperor as head of state
a group of diverse companies under common ownership and run as a single organization
an eating apple that somewhat resembles a McIntosh; used as both an eating and a cooking apple