Solo

Play alone, without any help from others

SP

Slave Pens, a Coilfang Reservoir instance in Zangarmarsh. Also, Shadow Priest. Also, Sunwell Plateau, a Level 70 25-man raid instance on the Isle of Quel'Danas

Spec

The allocation of talent points which determines how effective a character is at different roles

SPI

Spirit, a base statistic

SS

Southshore. Also Soul Stone, a warlock's conjured item which allows a player to resurrect himself after he dies. Also Stormstrike, an Enhancement Shaman attack that causes the target to be vulnerable to nature damage.

SSC

Serpentshrine Cavern, the Level 70 25-man raid instance of Coilfang Reservoir in Zangarmarsh

ST

Sunken Temple, also known as the Temple of Atal'Hakkar, an instance in Swamp of Sorrows

Stack

A number of identical items placed in a single bag slot, to conserve space. Only some items can be stacked. Also refers to multiple applications of a debuff or buff that increases its effects.

Stam

Stamina, a base statistic

Steamvault

Stocks

The Stockade, an instance in Stormwind

Str

Strength, a base statistic

Strat

Stratholme, an instance in Eastern Plaguelands

STV

Stranglethorn Vale, a zone in the Eastern Kingdoms

Succ

Succubus, a DPS/CC pet used by warlocks. Can seduce, charming an enemy.

SV

The Steamvault, a Coilfang Reservoir instance in Zangarmarsh

SW

Stormwind, home of the Humans

Tank

A character that is meant to hold the attention of the enemy while taking relatively little damage.

Tap

To do damage to a monster, claiming it. Once you have damaged the monster, you are the only one able to get experience and loot from it. Also refers to Warlocks' ability Life Tap, which reduces health in return for Mana.

Taunt

An ability that allows a player, usually a tank, to pull the attention of a monster off of another player and onto himself