knock-back

Từ điển Oxford Advanced Learner 8th

ˈknock-back f5 [knock-back knock-backs] BrE NAmE noun (informal)
a difficulty or problem that makes you feel less confident that you will be successful in sth that you are doing, especially when sb rejects you or sth you suggest or ask
•He had a few knock-backs, but eventually became one of the most highly-paid footballers in England.