https://www.etymonline.com/word/concerted https://www.etymonline.com/word/concerted says it is a past participle of "concern". Not sure if it is correct, but it

https://www.etymonline.com/word/concerted https://www.etymonline.com/word/concerted says it is a past participle of "concern". Not sure if it is correct, but it makes some sense if viewed with this in mind?