"In old English law. The estate or right of a mesne, (q. v.) Termes de la Ley". Alexander M. Burrill ... now shall the donee hold by twelve pence, for the mesnaltie which was four pence is extinct, and the law reserved the tenure upon the gift in taile, in respect of the mesnaltie, and when the mesnaltie is extinct, the former rent between the donor and donee is extinct also... Coke et al The judgement by the said statute of ... is a forejudger of the mesnalty, and that in two severall cases... Coke et al The other case is, where the tenant recovereth his acquitall in a writ of mesne, if he be not acquited afterwards, he shall have a writ of distringas ad acquietandum against the same mesne, and if he commeth not, he shall be forejudged by his default of the mesnality; and so if he commeth... Coke et al
Source: wiktionary