A vexatious or false defense, resorted to under the old system of pleading for purposes of delay and annoyance.
Cottrill v. Cramer, 40 Wis. 555 (1876):
“[S]ham pleas [are] pleas so palpably and manifestly untrue that the court will assume them to be so: pleas manifestly absurd. When answers or defenses admit of lawyer-like argument, such as courts should listen to, they are not sham in the sense of the statute. When it needs argument to prove that an answer or demurrer is frivolous, it is not frivolous, and should not be stricken off. To warrant this summary mode of disposing of a defense, the mere reading of the pleadings should be sufficient to disclose, without deliberation and beyond doubt, that the defense is sham or irrelevant.
In re BEAM, 93 N.J. Eq. 593 (1922):
While the courts sometimes use the terms ‘frivolous’ and ‘sham’ as meaning the same thing, and a motion to strike is often based on the ground that a plea is both frivolous and sham, there is nevertheless a clear distinction between the two in that a sham plea is good on its face, but false in fact, while a frivolous plea is one which on its face sets up no defense, although it may be true. A frivolous pleading is always assumed to be true, while a sham pleading must be proved to be false; the character of the former is determined by mere inspection, while that of the latter is usually determined by proof aliunde.
Fidelity Mut. Life Ins. Co. v. Wilkesbarre & H.R. Co., 98 N.J.L. 507 (1923):
The learned justice in the Supreme Court, struck it out on the ground that it was frivolous. In this we conceive he was legally correct, since a pleading cannot under the common-law rules applicable thereto be possessed of both legal infirmities at the same time [i.e., a pleading cannot be frivolous and sham at the same time]. At common law a plea was considered sham when it was palpably or inherently false, and from the plain or conceded facts in the case must have been known to the party interposing it to be false. Such a plea, says Chitty, ‘has always been considered a very culpable abuse of justice, and has often been censured and set aside with costs. 1 Chitty, Pl. 542; 1 Tidd’s Pr. 611; 2 Bouv. Law Dict. 680.A frivolous plea need not be false, but is palpably insufficient as a legal defense to the action, and hence legally insubstantial or frivolous, and therefore presumably interposed for the purpose of delay. 2 Bouv. Law Dict. 853. Under the common-law practice in New York and the Supreme Court rules, a plea might be condemned as either palpably false (sham) or frivolous, and could be struck out upon either ground, but was never summarily dealt with upon both grounds. Oakley v. Devoe, 12 Wend. 196; 1 Burrills Pract. 180; 21 R. C. L. 452, and cases cited.