What does "mood swing" mean?

A rapid and extreme changing in mood, from excessively happy to desperately miserable.

Mood swing

Common synonyms include: affective instability, caprice, change in mood, changement d'humeur, emotional fluctuation, emotional lability.

noun

noun ·Rare ·Advanced level

Noun

1
A rapid and extreme changing in mood, from excessively happy to desperately miserable.
"The worst thing about my wife's pregnancy was her awful mood swings."

"The worst thing about my wife's pregnancy was her awful mood swings."