ante meridiem

• am, AM
• a.m.
• antemeridiem

Unadapted borrowing from Medieval Latin ante merīdiem, from Latin ante (“before”) + merīdiem, accusative singular of merīdiēs (“noon, midday”).

ante meridiem (not comparable)

1. before noon, in the morning.
   • 1725, Church of Scotland. General Assembly, “Index of the ACTS of the General Assembly of the Church of Scotland held in the Year 1725, which are not here printed.”, in Compilation of Scans of The Principal Acts of the General Assembly of the Church of Scotland, 1721–1730, digitised for George Mosman in 2008, (mistitled by Google Books as if relating to 1721 only)‎^[1], Edinburgh, Scotland: James Davidson & Robert Fleming, 5th Section: The Principal Acts of the General Assembly of the Church of Scotland Conveened [sic] at Edinburgh, the 6th of May, 1725, page 29 of 1725 Section (5th page of Index):

     And 'tis earnestly recommended to the Synod to continue their Kindness to Mr Leask, according as his Circumstances do require, May 12. Sess. 6. ante meridiem.

• post meridiem