slack

adj. /slæk/ C1

松弛的；松散的

Not pulled tight or firmly stretched; loose.

仙境例句

The Dodo marked the course with string, but left it slack, so the circle was not quite round.

渡渡鸟用绳子圈出跑道，可绳子没拉紧，结果圈也不太圆。