Learn That Word

Synonyms for Catapult (same or very similar meaning)

WordNet sense 1 (a plaything consisting of a Y-shaped stick with elastic between the arms; used to propel small stones):
sling, slingshot

WordNet sense 2 (a device that launches aircraft from a warship):
launcher

WordNet sense 3 (medieval artillery used during sieges; a heavy war engine for hurling large stones and other missiles):
mangonel, onager, bricole, arbalest, arbalist, ballista, trebuchet, trebucket


From the ODE community, based on WordNetadd/edit