urgent business; pressing matter
Refers to something one must attend to immediately, often used when excusing oneself or explaining a sudden departure.
Something urgent has come up, so I'll excuse myself first.
I missed the meeting due to urgent business.
Something urgent came up, so I couldn't attend the meeting.
Please let me leave early because of an urgent matter.
An urgent matter came up the day before the trip.
I'll take care of an urgent matter and come back right away.