The Alternative key on a keyboard. To initiate the Access Key, type the allocated number/character while holding down the ALT key.
Some games allow you to have more than one character (I have two). If you do, you refer to your other characters as your alts, as in alter egos or alternates.
A key that, when used in combination with a mnemonic, opens a menu corresponding to a name on the menu bar. On a keyboard, the key may be ALT, Meta, or Extend char.