Quae Nihil Frustra
Defined in 2 dictionaries — Cyclopedic (1922), Ballentine's (1916)
The Cyclopedic Law Dictionary
Walter A. Shumaker and George Foster Longsdorf; ed. James C. Cahill · 1922
(Law Lat.) Which (does or requires) nothing in vain; which requires nothing to be done, that is to no purpose. 2 Kent, Comm. 53.
Ballentine's Law Dictionary
James A. Ballentine · 1916
Which (requires) nothing in vain.