See tempered in Webster's New World College Dictionary
adjective
having been given the desired temper, consistency, hardness, etc.: tempered steel
modified by addition of or mixture with other qualities, ingredients, etc.: the mercy in a tempered justice
having a (specified kind of) temper: bad-tempered
Music adjusted to a temperament, esp. equal temperament
See tempered in American Heritage Dictionary 4
adjective
Having a specified temper or disposition. Often used in combination: sweet-tempered; ill-tempered.
Adjusted or attuned by the addition of a counterbalancing element; moderated or measured: “prepare the country to expect hard choices and to appreciate tempered values and moderation in private and public life”(Haynes Johnson).
Made appropriately hard or flexible by tempering: a sword of tempered steel.
Having the requisite degree of hardness or elasticity. Used of glass or a metal.
Music Tuned to temperament. Used of a scale, an interval, semitone, or intonation.