Definition of "rue"
rue1
/ɹuː/
noun
uncountable
(archaic or dialectal) Sorrow; repentance; regret.
(archaic or dialectal) Pity; compassion.
rue2
/ɹuː/
verb
third-person singular simple present rues, present participle ruing or rueing, simple past and past participle rued
(archaic, intransitive) To feel compassion or pity.