temperature: [16] Like its relatives temper and temperament, temperature originally meant ‘mixture’ (Philemon Holland in 1601 wrote of ‘a temperature of brass and iron together’). The modern sense ‘degree of heat’ emerged in the late 17th century, and seems to have evolved from another early and now obsolete sense, ‘mild weather’. This reflected the ‘restraint’ strand of meaning in the word’s ultimate source, Latin temperāre, which also survives in English temperance and temperate. => temper
