expression, godan verb (-su)
make an enemy of; turn into an enemy; antagonize
Used when someone's actions cause another person or group to become hostile. Often implies a regrettable or avoidable outcome.
そんなことを言うと、彼を敵に回すことになるよ。
If you say something like that, you'll make an enemy of him.
あの政治家は発言で
That politician turned many citizens into enemies with his remarks.