n. the area on a billiard table behind the balkline
n. something immaterial that interferes with or delays action or progress
n. one of several parallel sloping beams that support a roof
n. 错误；失败；障碍（等于balk）
vt. 阻止；错过；推诿（等于balk）
vi. 犹豫；（马等）突然止步不前（等于balk）