yodan verb with 'ru' ending (archaic), intransitive verb
go away; become distant; fade away
Archaic intransitive verb meaning to move away, become distant, or fade. Replaced by 離れる (はなれる) in modern Japanese. Found in classical texts.
古語では「離る」は「遠ざかる」や「消え去る」の意で用いられた。
In classical Japanese, 離る was used to mean 'to go far away' or 'to disappear'.