私自
sī zì · HSK 7
without explicit approval
🤫 私 = private/selfish + 自 = self → acting on your own, off the record
自 — pictograph of a nose
自 originally depicted a human nose, shown frontally with the bridge and nostrils. Ancient Chinese pointed to their own nose to mean 'me,' so 自 shifted to mean 'self' or 'oneself.' A new character 鼻 was later created to carry the original 'nose' meaning.