Actio Non

Lat. In pleading. An abbreviation of actionem non, the emphatic words anciently used at the commencement of a special plea in bar; the defendant first averring generally, that the plaintiff "ought not to have or maintain his action," (actionem non habere,) and then proceeding to state the reason, — "because he says that, &c." Hence this whole preliminary formula, (literally translated in the modern forms,) has been technically termed the actio non, or actionem non.

Steph. Plead. 394, (Am. ed. 1824.) 1 Chitt. Pl. 906.

By the late rules of the English courts, (Hil. T. 4 Will. IV. 1, s. 10,) this clause is dispensed with.