0 to release the buckle (= metal fastener) of a shoe, belt, etc. so that you can remove it -- 解開…扣；鬆開
Finally, what about fidgety or naughty children who unbuckle their seat belts, either accidentally or deliberately?
Out of mischief he may well unbuckle his belt for that very reason.
As a result, the space toilet has been the first device activated on shuttle flights, after astronauts unbuckle themselves.
Then the man's boot unbuckles by itself.
Mosley unbuckles before the car comes to a rest, and jumps from the car trying to put out the flames.
Sarah unbuckles herself, breaks the window and exits the vehicle.
