Definition of: tierce

(tirs) noun
1. A former liquid measure equivalent in the United States to 42 wine gallons; a third of a pipe or butt.
2. A cask holding this amount, intermediate between a hogshead and a barrel.
3. In card games, a sequence of three cards of the same suit.
4. In fencing, the third standard position from which a guard, parry, or thrust can be made.
5. Eccl. The third canonical hour, nine a.m., or the office or service of that hour: often called undernsong.
6. Music An interval of a third.
7. A set of three. [<OF tierce, terce a third <L tertia, fem. of tertius]