possessing or using or characteristic of or appropriate to supernatural powers; "charming incantations"; "magic signs that protect against adverse influence"; "a magical spell"; "'tis now the very witching time of night"- Shakespeare; "wizard wands"; "wizardly powers"
Charming is the process of altering the "will" of a mob to force it to perform actions against its normal behavior at your command. For example to make it stop attacking your group and start attacking its fellow monsters. Charming is accomplished through magical effects. The duration of charm spells is usually random making this very powerful tool also a dangerous one.
The act turning a mob into a pet to help fight on your side.