A Southern contraction for "you all" and the best possible way to express ideas related to Southerners and rural areas.

"Y'all think I could borrow a lil' ol' cup of sugar?"
"Y'all better quit foolin' around in mah beans!"
"Where y'all think y'all are driving so fast on this highway?"
"Do y'all got any more of that there Beluga Caviar? We done run out at the tailgate!"
"Is that y'all's goat?"