1. (n.)tierce an old measure of capacity equivalent to one third of a pipe, or 42 wine gallons.
2. tierce a cask or vessel holding this quantity.
3. tierce (in piquet) a sequence of three cards of the same suit.
4. tierce Obs. a third.
Etymology: (1325–75; ME < MF, fem. of tiers < L tertiusthird)
Definition of 'tierce'
Princeton's WordNet
1. (noun)terce, tierce the third canonical hour; about 9 a.m.
2. (noun)three, 3, III, trio, threesome, tierce, leash, troika, triad, trine, trinity, ternary, ternion, triplet, tercet, terzetto, trey, deuce-ace the cardinal number that is the sum of one and one and one
3. (noun)one-third, third, tierce one of three equal parts of a divisible whole "it contains approximately a third of the minimum daily requirement"
Definition of 'tierce'
Webster Dictionary
1. (adj)tierce divided into three equal parts of three different tinctures; -- said of an escutcheon
2. (noun)tierce 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
3. (noun)tierce a cask larger than a barrel, and smaller than a hogshead or a puncheon, in which salt provisions, rice, etc., are packed for shipment
4. (noun)tierce the third tone of the scale. See Mediant
5. (noun)tierce a sequence of three playing cards of the same suit. Tierce of ace, king, queen, is called tierce-major
6. (noun)tierce a position in thrusting or parrying in which the wrist and nails are turned downward
7. (noun)tierce the third hour of the day, or nine a. m,; one of the canonical hours; also, the service appointed for that hour
Definitions of tierce 
