Highly pleasant to the taste. Beyond delicious. Just short of being so good where it would make you slap someone's momma. It's origin from statements such as "That was so damn good that it made my knees buckle."
Man.... Yo momma brought those collard greens to the church picnic yesterday. They was really bucklin'
Erik: Where were you last night kid, you missed an insane party?
Tony: O it don't matta I was bucklin' the seatbelt wit that girl from avalon.
Erik: Damn son, I'm impressed.