split up adjective 2verb 2split-up noun 1forms 3 adjective2 •Divided or separated. •(slang, no longer used) Of a person: having long legs.He should preferably be tall, weighty, well split up in the legs (especially from the hip-joint to the knee), neatly turned at the knee and ankle joints […] — 1913 verb2 •Cease to be together, break apart from the group.After she left to go travelling, my girlfriend and I split up.The soldiers split up into smaller squadrons to search the building. •separate, disassociate, cause to come apart.The brothers never behaved in class when they were together, so we had to split them up for the exam. split-up noun1 •A break-up.My desert-island, all-time, top five most memorable split-ups, in chronological order:[…] — 1995 formssplitting up · splits up · split-ups