The Severing Charm (Diffindo) is a charm used to precisely and accurately cut something. It is taught in second year charm classes, and if used inappropriately can cause death or injury.

This spell was invented in the fifteenth century  by wizarding seamstress Delfina Crimp. She made the spell because prior to her discovery, cutting spells were apt to burn or shred things. However, a fellow seamster nearly killed her after he raided her shop, having realised that she could do magic, and held her tied up. Nonetheless, upon being released to scratch a wart on her chin the wart brought her wand forth and she disapparated with a sack of gold.