Initialism of conscious, alert and oriented.
"The nurse documented that the patient was cao after regaining consciousness from the overdose."
"The cao weather made everyone want to stay inside and drink hot tea."
Initialism of Central Applications Office, the official body tasked with handling applications for students' first year of college.
"The history book details how the Cao clan rose to prominence as a powerful vassal state in eastern China during the late Spring and Autumn period of the Zhou dynasty."
A state of ancient China during the Zhou dynasty.
The word comes from the pinyin romanization of the Chinese character Cáo. It entered English as a phonetic spelling to represent this specific Mandarin surname or title.