Trebuchet
Trebuchet , noun
[Old French trebuchet, trebukiet, an engine of war for hurling stones, French trébuchet a gin, trap, a kind of balance, from Old French trebuchier, trebuquier, to stumble, trip, French trébucher.]
1.
A cucking stool; a tumbrel. — Cowell
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. [Obsolete]
Also: Trebucket