篮球里面knock it down是被击败的意思。
重点解释：
knock down
英[n?k daun] 美[nɑk da?n]
[词典] 拆卸; <非正>击倒; 拒绝; <非正>降价;
[例句]He died in hospital after being knocked down by a car
他被车撞倒后死在了医院。
The market might abandon the stock, and knock down its price
市场可能会抛售该股票，从而令其股价下跌。
A drunk driver knocked down and killed two girls
一个酒后驾驶的司机撞死了两个女孩儿。
They have since knocked down the shack.
从那以后他们拆掉了简陋的棚屋。
It manages to knock rents down to$ 1 per square foot.
成功地将租金降到每平方英尺1美元。