Caustic Smite

The next time you hit a creature with a melee weapon attack during this spell's duration, your weapon sprays caustic acid, and the attack deals an extra 1d4 acid damage to the target. In addition, the target of the attack and each creature within 5 feet of the target*, other than you, must make a Dexterity saving throw. A creature takes 2d4 acid damage on a failed save, or half as much damage on a successful one.
At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d4 for each slot level above 2nd.