黄昏(たそが)れるto fade into dusk, to fade into twilight, to decline, to wane, to abate, to look melancholic (of a person)

る-verb, Intransitive verb

1. 1.

   to get dark after sunset, to turn to dusk, to fade into twilight

2. 2.

   to decline (after a peak), to wane, to lose vigour

3. 3.

   to be lost in thought, to be in a pensive mood, to look melancholic

   Colloquial