The abbreviation for "once daily" is qd. I believe the Latin is quo diem.
Take orally once a day in the mornings. PO means per osin latin. q means once a day. AM is morning.
The medical term meaning once a day is "q.d." which stands for "quaque die" in Latin.
Qd
The Latin equivalent of the English phrase 'by the day' is the following: per diem. In English, the phrase commonly is used in the sense of the daily allowance. For example, salespeople may be allotted a certain amount of money to cover the expenses that come up in carrying out the job, such as travel, meals, and hotel stays.
"per diem" means per day. It comes from Latin.
once per day
Semel in Die (Latin: Once A Day)
Per diem is Latin for "per day" or "for each day". It usually refers to the daily rate of any kind of payment.
Translated literally from the English "for each day" would be 'per cotidiem' in Latin. Cotidie: Daily Dies ex Die: Each Day In Dies: Day by Day
Usually "per day" is abbreviated as "i.d", which comes from the Latin "in die". If you want to say twice per day, you would abbreviate it as b.i.d. (the b is for bi).
TID is Latin for three times per day. It is used on prescriptions by doctors - in order to indicate how many times per day a medication should be taken.