The Collaborative International Dictionary of English v.0.48:

Ninepins \Nine"pins\, n. pl.
   A game played with nine pins, or pieces of wood, set on end,
   at which a wooden ball is bowled to knock them down; bowling.
   [1913 Webster]

   Note: In the United States, ten pins are used for this game,
         which is therefore often called tenpins.
         [1913 Webster]

WordNet (r) 3.0 (2006):

ninepins
    n 1: a bowling game that is played by rolling a bowling ball
         down a bowling alley at a target of nine wooden pins [syn:
         ninepins, skittles]