The ability to have a beer in each hand and successfully take them down in an efficient mannor. Typically, this is looked upon as a badge of honor at fraternity parties and in the later innings of sporting events right before beer sales close.
This is similar to double fisting in the non-sexual manner but if you can find and ambeerdextrous chick, get up on that.
Dude, Davis has got to the be the most ambeerdextrous person I've ever seen. Not once have I seen an empty hand and if he's not crushing one on his head, he's opening another with his teeth. Genius.