A preliminary plea is a plea-in-law that raises a legal issue that does not relate to the merits of the proceedings but if sustained, could result in the proceedings (or part of them) being dismissed.
Mae ple rhagarweiniol yn ble cyfreithiol sy’n codi mater cyfreithiol nad yw’n berthnasol i rinweddau’r achos ond os bydd yn cael ei gynnal, gallai hynny arwain at wrthod achosion (neu rannau ohonynt).