An abrupt and unaccountable change of mood.
More example sentences
- Well she didn't sound too angry, but you never know she could have a severe mood swing; maybe she had just gone insane?
- ‘Sorry, sorry,’ I mumbled, taken aback by her sudden mood swing.
- She shot back, a mood swing suddenly in course, ‘I'm not a little girl anymore and I know what to do and what not to do!’
Definition of mood swing in:
- The US English dictionary