"session of a law court," c.1300 (attested from mid-12c. in Anglo-Latin), from Old French assise "session, sitting of a court" (12c.), properly fem. past participle of asseoir "to cause to sit," from Latin assidere (see assess). Originally "all legal proceedings of the nature of inquests or recognitions;" hence sessions held periodically in each county of England to administer civil and criminal justice.