Loosely defined and subjectively experienced general emotional condition.
A mood, while relatively pervasive, is typically neither highly intense nor sustained over an extended period of time. Examples of mood include happiness, sadness, contemplativeness, and irritability. The definitions of phrases to describe moods—such as good mood and bad mood—are imprecise. In addition, the range of what is regarded as a normal or appropriate mood varies considerably from individual to individual and from culture to culture.
Kuiken, Don, ed. Mood and Memory. Newbury Park, CA: Sage Publications, 1991.