What is the meaning of the word "temper"?

Definitions:

a characteristic, habitual or relatively temporary, state of feeling noun
- Whether they praised or cursed me depended on their temper at the time.
a disposition to exhibit uncontrolled anger noun
- Their temper was well known to all their employees.
a sudden outburst of anger noun
- My temper sparked like damp firewood.
bring to a desired consistency, texture, or hardness by a process of gradually heating and cooling verb
- temper glass
harden by reheating and cooling in oil verb
- temper steel