n. newly claimed facts or legal issues raised (brought up) by a defendant (the party being sued) to defend himself/herself/itself beyond just denying the allegations in the complaint filed by the person bringing the lawsuit (plaintiff). Such new matters are called "affirmative defenses." (See: answer)
NEW MATTER, pleading. All facts alleged in pleading, which go in avoidance of what is before, pleaded, on the opposite side, are called new matter. In other words, every allegation made in the pleadings, subsequent to the declaration, and which does not go in denial of what is before alleged on the other side, is an allegation of new matter; generally, all new matter must be followed by a verification. (q.v.) Gould, Pl. c. 3, Sec. 195; 1 Saund. 103, n. 1; Steph. PI. 251; Com. Dig. Pleader, E 32; 2 Lev. 5; Vent. 121; 1 Chit. PI. 538; 3 Bouv. Inst. n. 2983. In proceedings in equity, when new matter has been discovered by either plaintiff or defendant, before a decree has been pronounced, a cross bill has been permitted to bring such matter before, the court to answer the purposes of justice. After the answer has been filed, it cannot be introduced by amendment; the only way to introduce it, is by filing a supplemental bill. 4 Bouv. Inst. n. 4385-87; 1 Paige 200; Harring. Ch. 438.