Post diem
Defined in 2 dictionaries — Ballentine's (1916), Black's (1910)
Ballentine's Law Dictionary
James A. Ballentine · 1916
After the day.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
After the day; as, a plea of payment post diem, after the day when the money became due. Com. Dig. "Pleader," 2.
In old practice. The return of a writ after the day assigned. A fee paid in such case. Cowell.