Set-off meaning : To leave; to begin a journey or trip. To begin; to cause; to initiate. To cause to explode, let off. To make angry. To enhance by emphasizing differences. To offset, to compensate for: to reduce the effect of, by having a contrary effect. To deface or soil the next sheet; said of the ink on a freshly printed sheet, when another sheet comes in contact with it before it has had time to dry.