Tierce
Part of speech: noun
Definition: A cask whose content is one third of a pipe; that is, forty-two wine gallons; also, a liquid measure of forty-two wine, or thirty-five imperial, gallons. A cask larger than a barrel, and smaller than a hogshead or a puncheon, in which salt provisions, rice, etc., are packed for shipment. The third tone of the scale. See mediant. A sequence of three playing cards of the same suit. Tierce of ace, king, queen, is called tierce-major. The third defensive position, with the sword hand held at waist height, and the tip of the sword at head height. An ordinary that covers the left or right third of the field of a shield or flag. (R. C. Ch.) The third hour of the day, or nine a. m,; one of the canonical hours; also, the service appointed for that hour.
Terce
Part of speech: noun
Definition: The third canonical hour; about 9 a.m.