Boomerang and Ballista

Boomerang noun - A curved piece of wood; when properly thrown will return to thrower.

Ballista and boomerang are semantically related In some cases you can use "Ballista" instead a noun "Boomerang".

Ballista noun - An engine that provided medieval artillery used during sieges; a heavy war engine for hurling large stones and other missiles.

Boomerang and ballista are semantically related in arm topic. Sometimes you can use "Boomerang" instead a noun "Ballista".