Seer

A seer (or seeress if female) is usually someone with the ability to predict the future or see things hidden from mundane eyes, like a clairvoyant or a prophet.

Tauren
The three most powerful healers in a tauren tribe support the chief, the most powerful of whom takes the title seer. A chief generally consults his seer and her two contemporaries before making a decision, but this consultation is not required.

Other types

 * Grayhorn is a windseer.
 * Saberon Cold-Eye is a boneseer, who divines the future using the remains of the dead.
 * Ghrent is a skyseer.
 * Cinderseers
 * Runeseers
 * Crystal is a sea seer
 * Voidseers
 * Stormseer
 * Flameseer

The Seers
All priest trainers that are tauren (except Tahu Sagewind, their leader) carry the title "Seer", and the level 20 class quest for tauren priests is called A Seer's Staff (tauren) - although the goblin one is called the same - and mentions that the player would "become a full seer" through this mission, implying that the seers and tauren priests are identical or have merged - or have been merged by Blizzard. They are associated with the Sunwalkers and share (re)founding members, but appear to be an independent order.

Named

 * Akubar the Seer
 * Blindeye the Seer
 * Seer Graytongue
 * Seer Janidi
 * Seer Jovar
 * Seer Kanai
 * Seer Nakha
 * Seer Olum
 * Seer Ravenfeather
 * Ruuna the Blind
 * Takar the Seer
 * Seer Skaltesh
 * Udalo
 * Ul'Tomon
 * Voren'thal the Seer
 * Seer Wiserunner
 * Seer Yagnar
 * Warp-Scryer Kryv
 * Seeress Weng Wu
 * Velen
 * Drek'Thar

Units

 * Unbound Seer
 * Smolderthorn Seer
 * Deepfin Seer
 * Frostmane Seer
 * Lost One Seer
 * Umbrafen Seer
 * Wrekt Seer
 * Blacksilt Seer
 * Greymist Seer
 * Grimscale Seer
 * Burning Blade Seer
 * Death's Head Seer
 * Razormane Seer
 * Stonesplinter Seer
 * Stonevault Seer
 * Dragonflayer Seer