Temperare (to mix correctly) is the Latin origin of wors like "temperature" and "tempering"; it and "tempo" come, in turn, from tempus (time or season). Thus, the word "temper" can refer (at least informally) to any time- and temperature-sensitive process (as for chocolate tempering or tempered glass), a material's thermo-mechanical history (including cold work and cryogenic hardening), or even its composition.