from
The Collaborative International Dictionary of English v.0.48
Anneal \An*neal"\, v. t. [imp. & p. p. {Annealed}; p. pr. & vb.
n. {Annealing}.] [OE. anelen to heat, burn, AS. an?lan; an on
+ ?lan to burn; also OE. anelen to enamel, prob. influenced
by OF. neeler, nieler, to put a black enamel on gold or
silver, F. nieller, fr. LL. nigellare to blacken, fr. L.
nigellus blackish, dim. of niger black. Cf. {Niello},
{Negro}.]
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.
[1913 Webster]
2. To heat, as glass, tiles, or earthenware, in order to fix
the colors laid on them.
[1913 Webster]