I. (ˌ)pər-ˈdē-əm, -ˈdī- adverb
Etymology: Medieval Latin
Date: 1520
: by the day : for each day
II. adjective
Date: 1809
1. : based on use or service by the day : daily
2. : paid by the day
III. noun
( plural per diems )
Date: 1812
1. : a daily allowance
2. : a daily fee