1. To modify by the addition of a moderating element; to moderate: The teacher tempered her criticism of Tom's essay with a few words of encouragement.
2. To bring to a desired consistency, texture, hardness, or other physical condition by or as if by blending: In order to have the right color for painting his picture, Tim tempered it with some oil to make the consistency and color better.
3. To harden or to strengthen metal or glass by an application of heat or by heating and cooling: In order to make the horseshoes for his customers, the blacksmith at the outdoor museum had to temper the steel in order to hammer it to the correct size.
4. To strengthen through experience or hardship; to toughen: There are soldiers who have been tempered by combat.
5. To adjust finely, to attune: Mark developed a portfolio that is tempered to the investor's needs and desires.
5. Etymology: from Middle English temprien, tempren, from Old English temprian, "to moderate, to regulate, to mingle", and Old French temprer (French temperer), which both derive from Latin temperare, "to mix in due proportion, to combine properly, to moderate, to regulate", probably from temper-, a variant of tempor- stem of tempus, "time, pertaining to time, a season".

1. Marked by having a specific disposition: From the very beginning, little Finn has been a very sweet-tempered little boy.
2. Relating to something that is made hard or flexible by using heat: In order to have his house as secure as possible, Mike Smith wanted to have tempered glass windows, which was supposed to be nonbreakable, and a heavy security door installed.

Having a bad temper; ill-conditioned; morose, cross, peevish.