WordNet (r) 3.0 (2006):

troika
    n 1: a Russian carriage pulled by three horses abreast
    2: the cardinal number that is the sum of one and one and one
       [syn: three, 3, III, trio, threesome, tierce,
       leash, troika, triad, trine, trinity, ternary,
       ternion, triplet, tercet, terzetto, trey, deuce-
       ace]
    3: a modern Russian triumvirate