meaning of trebucket
1. A cucking stool; a tumbrel.
2. A military engine used in the Middle Ages for throwing stones, etc. It acted by means of a great weight fastened to the short arm of a lever, which, being let fall, raised the end of the long arm with great velocity, hurling stones with much force.
3. A kind of balance for weighing.
4. medieval artillery used during sieges; a heavy war engine for hurling large stones and other missiles