(in tennis or other racket sports) a period of practice play, especially before formal play begins.
〈英〉（网球或使用球拍的其他体育运动项目）（尤指赛前的）练习
Example sentencesExamples
Don't get me wrong, I enjoy a knock-up on the courts.
I have been playing more squash recently and in the knock-up I again felt confident and was pulling off shots that surprised and impressed me for their accuracy and technique.
Federer genuinely looks as if he's having a gentle knock-up.
However, it seemed as if the fans only had eyes for Anna and some of the more red-blooded males couldn't refrain from wolf whistling when she removed her tracksuit top at the end of the knock-up!
The final decision was deferred until after a final practice session today, but a light knock-up with Courteau confirmed her worst fears and Mauresmo sat courtside in the Rod Laver Arena with her head buried in a towel.