TresayleTres"ayle`\ (tr[e^]s"[=a]l`), n. [F. trisa["i]eul, from L. tris, tres, three + F. a["i]eul grandfather. Cf. Besaiel, and see Ayle.] A grandfather's grandfather. [Obs.] Writ of tresayle (O. Eng. Law), a writ which lay for a man claiming as heir to his grandfather's grandfather, to recover lands of which he had been deprived by an abatement happening on the ancestor's death. --Mozley & W.