[IBM, probably from slang belly up] Yet another synonym fOR "broken" OR "down". Usually connotes a majOR failure. A system (hardware OR software) which is "down" may be already being restarted befORe the failure is noticed, whereas one which is "casters up" is usually a good excuse to take the rest of the day off (as long as you' re not responsible fOR fixing it). [Jargon File]