(noun)
a tendency to be irritable or sensitive and thus behave/react in a very emotional or angry way;
e.g. He showed much more temperament when he was stressed.
(noun)
a process during the tuning of a musical instrument such as piano during which the intervals between various notes are adjusted so that they are equal, or the final state of an instrument after this process;
e.g. They praised the piano's temperament and sound.
(noun)
the action or process of modifying or adjusting (tempering) something;
e.g. She had almost finished with her temperament of the laboratory equipment.