The drowsy and slightly painful state experienced after eating a standard BBQ meal, which is inevitably consumed in very large quantities.
Chipotle's "Barbacoa" burrito is only one example of a large quantity of BBQ beef. While one may very well experience drowsiness or discomfort after its consumption, a true barbacoma can not be had without at least one of the following sides: sweet potato pie, sweet corn, cornbread, or baked beans.
Excuse me while I take a nap. After eating all that food at the BBQ joint, a barbacoma is definitely coming on.
The drowsy, listless feeling endured after noshing on way too much food. Specifically, barbacoma often pertains to the episode following consumption of Chipotle burritos (perhaps filled with barbacoa), though it is applicable to large quantities of food in general.
After eating all that Chipotle, I do believe I've slipped into barbacoma and will be unable to accomplish anything for the foreseeable future. Two burritos are too many.