source: [怒り_上野｜無料GIF画像検索 GIFMAGAZINE 3021069]

1. in singular a person's state of mind seen in terms of their being angry or calm:

(一時的な)気分, 機嫌 (!具体例ではa ～; その際修飾語を伴う)

e.g. he rushed out in a very bad temper.

a tendency to become angry easily:

怒りっぽい性格, かっとする気質

e.g. I know my temper gets the better of me at times.

an angry state of mind:

〖通例a ～〗 短気, かんしゃく

e.g. Drew had walked out in a temper

e.g. I only said it in a fit of temper.

2. the degree of hardness and elasticity in steel or other metal:

(鋼などの)硬度, 調質度

e.g. the blade rapidly heats up and the metal loses its temper.

1. improve the hardness and elasticity of (steel or other metal) by reheating and then cooling it.

〈鋼など〉を鍛える, …の硬度を高める

improve the consistency or resiliency of (a substance) by heating it or adding particular substances to it.

2. (often be tempered with) serve as a neutralizing or counterbalancing force to (something):

｟かたく｠ «…で» …を加減, 抑制する; 〈感情など〉の強さを緩和する «by, with»

e.g. their idealism is tempered with realism.

3. tune (a piano or other instrument) so as to adjust the note intervals correctly.

〘楽〙 〈ピアノなど〉を調律する

refrain (or fail to refrain) from becoming angry.

in an irritable mood.

temperer noun

Old English temprian‘bring something into the required condition by mixing it with something else’, from Latin temperare ‘mingle, restrain’. Sense development was probably influenced by Old French temprer ‘to temper, moderate’. The noun originally denoted a proportionate mixture of elements or qualities, also the combination of the four bodily humors, believed in medieval times to be the basis of temperament, hence temper (sense 1 of the noun) (late Middle English). Compare with temperament.