ray gun

WordReference Random House Unabridged Dictionary of American English © 2025

ray′ gun′, 

1. a gun that can fire bursts of usually destructive or lethal rays:
   a science fiction novel whose hero has a ray gun made of gold.
2. a child's futuristic toy gun that emits sparks, whirring noises, etc.
• 1930–35

Collins Concise English Dictionary © HarperCollins Publishers::

ray gun noun

1. (in science fiction) a gun that emits rays to paralyse, stun, or destroy