An enemy or foe; one who has enmity at heart. The Lord shall take vengeance on his adversaries. Nahum 1:2. In scripture, Satan is called THE adversary, by way of eminence. Peter 5:8.

An opponent or antagonist, as in a suit at law, or in single combat; an opposing litigant.

Opposed; opposite to; adverse. In law, having an opposing party, as an adversary suit; in distinction from an application, in law or equity, to which no opposition is made.