Someone or something is surrounded by a general feeling of distrust, negativity, pessimism, or uncertainty, especially as results from a particular negative event in the recent past. After a year of unmitigated success, a cloud now hangs over the team, as a criminal investigation into allegations of domestic abuse against their captain. A cloud hangs over the future of the business, as customers continue to move their shopping habits online and away from brick-and-mortar retailers like this.