Taunt
A taunt is a move designed to provoke, annoy, or mock opponents, or to just celebrate a good move or combo. Up until Brawl, there was a limit of one taunt per character. In Brawl, however, each character has three different taunts. To use a taunt, in SSB or Melee one would simply have to press any direction on the Directional-Pad (or "D-pad"(. In Brawl, the direction one presses on the D-pad influences which taunt is used. Interestingly, Luigi and Snake are, so far, the only characters who's taunt can inflict damage.
In Melee, Pichu had two taunts. A possible nod to this occurs in Brawl, where C. Falcon also has an extra taunt, depending on what direction he is facing.
Each taunt is different between every character. However, there is one thing certain with taunts. Taunts will always either have the character speaking, yelling out a battle cry, or doing a motion (such as dancing). Some people take advantage of taunts where players talk within Taunt Matches.
Marth is the only character in non-Japanese versions that still speaks Japanese. However, some "speaking" taunts change between languages. A notable example is Jigglypuff, whose dialogue changes to reflect its name in other languages, such as its Japanese name, "Purin."