It's an object that's designed to be hurled or shot forward, like a bullet or a rocket
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cannon ball, cannonball, round shot - a solid projectile that in former times was 
fired ... a rocket having two or more rocket engines (each with its own fuel) that 
are fired... [DOC] [TLE] projectile - Dictionary Definition : Vocabulary.com [PAR] A projectile is a type of weapon that is propelled towards its target.