Wall
A creature type with no particular rules meaning. Older cards with the Wall creature type but without defender had an unwritten ability that precluded them from attacking. Those cards have received errata in the Oracle card reference to have defender. Some older cards that referenced the Wall creature type have also received errata. See Defender.

Win the Game
There are several ways to win the game. See rule 104, "Ending the Game," and rules 810.8 (for additional rules for Two-Headed Giant games) and rule 809.5 (for additional rules for Emperor games).

Wither
A keyword ability that affects how an object deals damage to a creature. See rule 702.79, "Wither."

Wizardcycling
See Typecycling.

World
A supertype that’s normally relevant on enchantments. See rule 205.4, "Supertypes." See also World Rule.

World Rule
A state-based action that causes all permanents with the world supertype except the one that has had the world supertype for the shortest amount of time areput into their owners’ graveyards. See rule 704.5k.