Power Word Kill

9th-level enchantment
Casting Time: 1 action
Range: 60 feet
Components: V
Duration: Instantaneous

You utter a word of power that can compel one creature you can see within range to die instantly. If the creature you chose has 100 hit points or fewer, it dies. Otherwise, the spell has no effect.

Spell Lists. Bard, Sorcerer, Warlock, Wizard

Source: Player's Handbook, Dungeon Master's Guide