on stun

prepositional phrase2

1. •
   An intensity setting of the fictional phaser energy weapon, from the television series Star Trek (1966–69), which non-lethally stuns its target.

   • Captain James Kirk: "Set your phaser on one quarter. I'll leave mine on stun." — 1966
2. •
   (informal) (usually after a plural noun), to a degree that is stunning.

   • It's all happening at once, right? All news streams on stun. Everything happening at the same time. — 2020