adj .
emotionally unpredictable ; rapidly changing in mood 감정의 변화를 예측하기 어려운, 변덕스러운 ; 기분이 급작스럽게 바뀌는

• A person with a _____ personality is one who changes rapidly and unpredictably between one mood and another.
• _____ Helen was crying one minute, laughing at next.