v. t. | 1. | To subject to great heat, and then cool slowly, as glass, cast iron, steel, or other metal, for the purpose of rendering it less brittle; to temper; to toughen. |
2. | To heat, as glass, tiles, or earthenware, in order to fix the colors laid on them. |
Verb | 1. | anneal - toughen (steel or glass) by a process of gradually heating and cooling; "temper glass" |