trebuchet

US /ˈtreb.ʊ.ʃeɪ/
UK /ˈtreb.ʊ.ʃeɪ/
1.

trebuchet

a large device used in wars in the past for throwing large rocks, for example at the walls of a castle that was being attacked:

:
The action of a trebuchet was similar to that of a giant catapult.