fickle

/ˈfɪkəl/
adjective
  1. Likely to change opinions, loyalties, or interests suddenly and without good reason; not constant or dependable.
    • The weather in spring is fickle, sunny one moment and rainy the next.
    • Fickle fans stopped supporting the team after just two losses.
    • She is fickle about her hobbies, switching from painting to guitar every few weeks.
Antonyms