nature; disposition; temperament
Refers to a person's inherent character or temperament. Often used in phrases like たちが悪い (bad-natured) or たちのいい (good-natured).
He has a bad nature, so be careful.
Describes the inherent quality or type of something, not just people. Often used in set phrases like たちの悪い病気 (a nasty illness).
That person has a good disposition, doesn't he?
This cold is a nasty one and just won't go away.
Usually written in kana; the kanji 質 is rare for this reading.
Katakana spelling sometimes used for emphasis or in informal writing.
Kanji spelling is possible but uncommon; may be confused with しつ.
A native Japanese noun of uncertain origin, conventionally written 質.