To disband means to break up a group and stop working together as an organized unit. When a club disbands, its members go their separate ways and the club ceases to exist. When a rock band disbands, the musicians stop performing together and might pursue solo careers or join other bands.

The word suggests something more official than just drifting apart. A group of friends might stop hanging out as much, but they haven't disbanded because they were never formally organized. However, when the student council disbands at the end of the school year, that's an official ending for an organized group with a specific purpose.

Sometimes groups disband because they've accomplished their goal. A committee formed to plan the school carnival might disband once the event is over. Other times groups disband because members disagree, run out of money, or lose interest. Military units disband when a war ends and soldiers return home.

The opposite of disbanding is forming or assembling. While getting people together to form a group can take effort and excitement, disbanding can happen quietly, when a group's time has simply come to an end.