(a) A set or course of thirty masses for the dead, sung on the same day or spread over several days, a trental; also, a poem describing a particular trental [quot. a1500 Trental]; also, a payment for singing such masses; ~ messe; ~ of messes; (b) gilden (golden, grege, pope, seinte gregori, etc.) ~, gret ~ of seinte gregori, a trental attributed to Pope Gregory consisting of ten sets of three masses for the dead to be sung on ten chief feast days of the year (Christmas, Epiphany, Easter, etc.) [see quot. c1390 in (a)];—also pl.; also as the title of a poem describing this trental [1st & 2nd quots.]; also, a payment for singing this trental [quot. c1475]; (c) ?a period of thirty days during which a trental is sung; ?the thirtieth day after burial when a commemorative mass for the dead is sung [cp. month-mind(e n.].