rue      
verb [ T ]  old-fashioned or literary uk/ruː/ us/ruː/  rueing or ruing | rued
 对…感到懊悔;对…感到后悔;因为…感到遗憾
to feel sorry about an event and wish it had not happened
 Idiom   
rue the dayidiom  追悔莫及
to feel very sorry about an event
  She'll rue the day (that) she bought that house. 她买了那座房子,以后会追悔莫及的。