Anneal v. t. (past & past part. annealed; pres. part. annealing)
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.