idiosyncrasy
US /ˌɪd.i.əˈsɪŋ.krə.si/
UK /ˌɪd.i.əˈsɪŋ.krə.si/
1.
khí chất
a strange or unusual habit, way of behaving, or feature that someone or something has:
:
•
She often cracks her knuckles when she's speaking - it's one of her little idiosyncrasies.