The Disband unit ability removes a unit, deducts its point value from the player's score, and returns half of its cost (rounded down to the nearest star). Like other unit abilities, Disband can only be used on any given turn by units that have not performed any other actions that turn, e.g. moving. Disband is unlocked by the Free Spirit technology.
Disbanding a super unit returns five stars. (Super units have a theoretical cost of 10 stars.) Disbanding a Ship or Battleship only returns half the cost of the base unit it carries. No portion of the cost of the upgrade from a Boat is returned.
The icon for Disband is three stars arranged in a triangle. Prior to update 2.0.44, the icon was the generic tribe head.