v (intransitive) To lose strength and become weak; to be in a state of weakness or sickness. (defdate|from 14th c.)
v (intransitive) To pine away in longing for something; to have low spirits, especially from lovesickness. (defdate|from 14th c.)
v (intransitive|now|_|rare) To affect a languid air, especially disingenuously. (defdate|from 18th c.)