1.  troika(n = noun.artifact) - a Russian carriage pulled by three horses abreast;
is a kind of carriage, equipage, rig

2.  troika(n = noun.quantity) 3, deuce-ace, iii, leash, tercet, ternary, ternion, terzetto, three, threesome, tierce, trey, triad, trine, trinity, trio, triplet - the cardinal number that is the sum of one and one and one;
is a kind of digit, figure

3.  troika(n = noun.group) - a modern Russian triumvirate;
is a kind of triumvirate

troika, n.
1 a a Russian vehicle with a team of three horses abreast. b this team.
2 a group of three people, esp. as an administrative council.

Etymology:
Russ. f. troe three