a difficulty or problem that makes you feel less confident that you will be successful in something that you are doing, especially when somebody rejects you or something you suggest or ask （尤指被人拒绝时受到的）挫折，挫伤，打击 He had a few knock-backs, but eventually became one of the most highly paid footballers in England. 他有一些挫败感，但最终成为英格兰薪水最高的足球运动员之一。