1 to become less strong; to make sb/sth less strong (使)变弱:
The illness had left her weakened.她病愈之后,身体变得很虚弱。The building had been weakened by the earthquake.地震过后,那幢大厦的结构变得不如以前稳固。 [OPP] strengthen 反义词为strengthen
2 to become less certain or firm about sth 变得犹豫或不大坚定:
She eventually weakened and allowed him to stay.她终于不再坚持,同意让他留下来。