事件【じけん】
event, affair, incident, case, plot, trouble, scandal
条件【じょうけん】
condition, term, requirement, qualification, prerequisite
要件【ようけん】
important matter, requirement, requisite, necessary condition, sine qua non
案件【あんけん】
matter (to discuss), item (on the agenda), issue, topic, case, (court) case
無条件【むじょうけん】
unconditional
用件【ようけん】
business, thing to be done, something that should be performed, information that should be conveyed