In curling, the second is the person who delivers the second pair of stones. On most teams, where the second does not act as skip or vice, the second will sweep for each of his teammates. Due to the free-guard rule, which prevents some early stones from being removed from play by the leads, the second is usually a curler with a high degree of proficiency throwing takeouts, peels, and other power shots.
References
Second (curling) Wikipedia(Text) CC BY-SA