1. the tendency to have frequent changes in mood or to be temperamental and unpredictable in emotional state

Examples

• Her moodiness made it difficult for her friends to know how to approach her.
• The teenager’s moodiness was typical for his age.
• His moodiness at work affected the entire team’s productivity.
• She blamed her moodiness on lack of sleep and stress.
• The artist’s moodiness was reflected in his unpredictable paintings.
• After starting the new medication, his moodiness decreased significantly.