Origin: Latin suffix -ary
Adversary has 3 different meanings across 2 categories:
someone who offers opposition
"The chess player treated his old rival not just as a competitor, but as a true adversary whose sharp tactics constantly challenged his own strategy."
An opponent or rival.
"The chess player studied his adversary's opening moves carefully to find a weakness in their strategy."
The Devil; Satan.
"The preacher warned that no earthly power could defeat our true adversary, for he is the only enemy who truly hates us."