per diem

Per diem is an adverb meaning By the day and is usually used after the person or thing it modifies. Per is employed as a preposition, in this case meaning 'for or in each or every' and used to is to separate the word in the expression. Latin, literally per day, "daily" would be a good synonym. For reckoned on a daily basis.

The phrase per diem is used primarily in the business world such as a daily allowance for expenses;
i.e.The traveling salesman was given a fixed per diem.

Also used in legal arenas, and to some extent as a medical term to take prescribed amounts of medications a specific number of times per diem, or per day.

The Per Diem Expense allowance given to business travelers actually tends to vary by institution, time and location of travel. As allowed for by most grants given to hard science, as I can attest, the Per Diem is actually quite generous, and expenses can also include things like car rental and general entertainment. In fact, it has been a vested interest of many a graduate student to cause the National Science Foundation to pay for more alcohol than they will ever know....

Per di"em (?). [L.]

By the day; substantively (chiefly U. S.), an allowance or amount of so much by the day.

 

© Webster 1913