per diem

[per dee-uh m, dahy-uh m] /pər ˈdi əm, ˈdaɪ əm/
noun
1.
by the day; for each day.
2.
a daily allowance, usually for living expenses while traveling in connection with one's work or being employed at a distance from one's home:
a per diem for lawmakers while the legislature is in session.
3.
paid by the day.
Origin
1510-20; < Latin
Can be confused
per annum, per capita, per diem.
British Dictionary definitions for per diem

per diem

/ˈpɜː ˈdaɪɛm; ˈdiːɛm/
adverb
1.
every day or by the day
noun
2.
  1. an allowance for daily expenses, usually those incurred while working
  2. (as modifier): a per-diem allowance
Word Origin
from Latin
Word Origin and History for per diem

Latin, literally "by the day," from per (see per) + diem, accusative singular of dies "day" (see diurnal). As a noun from 1809.

per diem in Culture
per diem [(puhr dee-uhm, deye-uhm)]

A Latin phrase meaning “by the day.” Traveling sales reps or government workers often are paid a per diem, meaning an allowance out of which to cover daily expenses while traveling.