Godan verb with 'ru' ending, Intransitive verb
to be renewed; to change
長年の習慣はなかなか改まらない。Old habits die hard. to be improved; to be reformed; to be revised; to be corrected
to stand on ceremony; to be formal
to take a turn for the worse (of an illness); to take a serious turn
esp. 革まる
Also written 革まる【あらたまる】