In English means: "Dumb... and (still) walking". It is used to describe the foolness of a person who is completely unaware of what is going on around him/her. e.g.
Person 1: "Check out this car which just got out of the gas station!" Person 2: "OMG! the driver took off with the gas nozzle still inside!" Person 1: "...and he has no idea" Person 2 (laughin): "ghecheh w mecheh"
"Bala daff byor2ous" - Lebanese Slang: translates into "he doesn't need a tambourine, to dance" and refers to a person that is already over-dynamic / risk-taking, without an external push...
Sample Conversation:
Husband: Our son really enjoyed bunjee jumping, today... I'm thinking about giving him the number of that skydiving center!
Wife: don't give him ideas... bala daff byor2ous... both of you are going to get me a heart attack, one day...
