Yes, BARBEQUE is a Scrabble word!

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

Is it a valid word?

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

meat that has been barbecued or grilled in a highly seasoned sauce
a cookout in which food is cooked over an open fire; especially a whole animal carcass roasted on a spit
a rack to hold meat for cooking over hot charcoal usually out of doors

Also: cook out.