The term 'OPPOSITE OF UP' can be answered in three different ways. The first answer is DOWN, which is a four letter word meaning the opposite direction of up. The second answer is MOODY, which is a five letter word meaning having a sullen and gloomy disposition, which is the opposite of being cheerful and upbeat. The third answer is ABED, which is a four letter word meaning to be in bed, which is the opposite of being awake and active.