tierce in WordNet English dictionary

1. the cardinal number that is the sum of one and one and one
   three  3  III  trio  threesome  tierce  leash  troika  triad  trine  trinity  ternary  ternion  triplet  tercet  terzetto  trey  deuce-ace 
   
2. one of three equal parts of a divisible whole
   "it contains approximately a third of the minimum daily requirement"
   one-third  third  tierce 
   
3. the third canonical hour; about 9 a.m.
   terce  tierce