Pro re nata
Defined in 2 dictionaries — Ballentine's (1916), Black's (1910)
Ballentine's Law Dictionary
James A. Ballentine · 1916
For the occasion as it happens.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
For the affair immediately in hand; adapted to meet the particular occasion. Thus, a course of judicial action adopted under pressure of the exigencies of the affair in hand, rather than in conformity to established precedents, is said to be token pro re nata.