tierce †third part XV; third hour of the day (9 a.m.); canonical office said at this hour (TERCE) XIV; wine measure or cask XVI; third of the parries in fencing; sequence of three playing cards XVII; (mus.) note two octaves and a major third above a fundamental note XVII; (her.) division of a shield into three equal parts XIX. — (O)F. t(i)erce :- L. tertia, sb. use of fem. of tertius THIRD.

Tierce

a band or company of soldiers; a cask of wine, hence, a similar amount of other commodities; the third part of a thing or group of people or things.

Examples : tierce of beef (a cask), 1800; of coffee berries, 1825; of French claret (cask), 1707; of honey (a cask), 1585; of pork (a cask), 1800; of soldiers (a band or company); of tobacco, 1886; of wine (a cask).

tierce (Fr. noun). Third.
1. Interval of a 3rd, major or minor.  

2. 4th of series of natural harmonics.

3.   Org. stop of same pitch as similarly-named harmonic.

tierce Obsolete measure of wine cask; ⅓ of a pipe, i.e. about 35 imperial gallons (160 litres).