Disruption; coming apart; a separation and dispersion of the parts or members; as, a break-up of a meeting, assembly, or dinner party; the break-up of a spacecraft on re-entry into the atmosphere. [1913 Webster]
the termination of a relationship; a break-up of the government; the break-up of a marriage; the break-up of a business partnership; the break-up of a comedy team. [WordNet 1.5]