Adept
The Adept was one of several NPC Classes introduced in Dungeons & Dragons 3rd edition, a direct response to NPCs and PCs now running off of the same system. It takes the place of Wokani from BECMI, sharing many of the same spells and maximum of 6th level.
The Adept was a divine spellcasting class that mingled elements of cleric and wizard. It could cast divine spells of up to 5th level and prepared them in advance, but it also possessed a familiar.
Infamously occupied the same row as many PC classes in the Tier System, unlike any of its brethren, and was actually considered higher tier than the monk, the paladin, and the fighter. Yes, really. This was a spellcaster's edition, son!
The other NPC Classes of that addition were the Aristocrat, the Commoner, the Expert and the Warrior.