In conventional usage, boredom, ennui, or tedium is an emotion characterized by uninterest in one's surrounding, often caused by a lack of distractions or occupations. Although, "There is no universally accepted definition of boredom. But whatever it is, researchers argue, it is not simply another name for depression or apathy. It seems to be a specific mental state that people find unpleasant—a lack of stimulation that leaves them craving relief, with a host of behavioral, medical and social consequences." According to BBC News, boredom "...can be a dangerous and disruptive state of mind that damages your health"; yet research "...suggest[s] that without boredom we couldn't achieve our creative feats."

Emotions are physical and mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is no scientific consensus on a definition. Emotions are often intertwined with mood, temperament, personality, disposition, or creativity.