State
Noun
じょうたい
妹は、精神状態が不安定であるということを私に打ち明けた。
My little sister told me about her unstable state of mind.
The condition that something is in and the appearance of it is the condition / state of that object.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.