Dr. Bill says:
online etymology dictionary has:
barbecue
1657, from Amer.Sp. barbacoa, from Arawakan (Haiti) barbakoa "framework of sticks," the raised wooden structure the Indians used to either sleep on or cure meat. Originally "meal of roasted meat or fish," modern popular noun sense of "grill for cooking over an open fire" is 1931.

He also suggests looking at
http://www.worldwidewords.org/qa/qa-bar1.htm