Ultima Ratio
Defined in 3 dictionaries — Cyclopedic (1922), Ballentine's (1916), Black's (1910)
The Cyclopedic Law Dictionary
Walter A. Shumaker and George Foster Longsdorf; ed. James C. Cahill · 1922
The last resort. ULTIMA VOLUNTAS (Lat.)
In old English law. Last will; the last will. In testamento suo, in ultima voluntate sua, in his testament, in his last will. Reg. Grig. 244b. ULTIMA VOLUNTAS TESTATORIS EST perimplenda secundum veram intentlonem suam. The last will of a testator is to be fulfilled according to his true intention. Co. Litt. 322; Broom, Leg. Max. (3d London Ed.) 505.
Ballentine's Law Dictionary
James A. Ballentine · 1916
The last reason or resort.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
Lat. The last argument; the last resort; the means last to be resorted to.