event; affair; incident; case; plot; trouble
condition; term; requirement; qualification; prerequisite
business; thing to be done; something that should be performed; information that should be conveyed
matter (to discuss); item (on the agenda); issue; (court) case
major incident; major happening; big scandal
important matter; requirement; requisite; necessary condition
the matter you have been talking about
personnel expenses; labor cost; labour cost; indirect labour costs; indirect labor costs
subject; title; subject (of an email); subject line
number of events (e.g. accidents, crimes, meetings, housing starts, hits on a web page)
several items; many items
most important condition (for); first prerequisite
rare event; unexpected event
disgraceful incident; scandalous affair; untoward (deplorable) event
aforementioned; previous case; antecedent
September 11 attacks; 9/11
(formal) topic at hand; current topic