fickle

/ˈfɪk.əl/
adjective
  1. 1

    Quick to change one’s opinion or allegiance; insincere; not loyal or reliable.

  2. 2

    Changeable.

verb
  1. 1

    To deceive, flatter.

  2. 2

    To puzzle, perplex, nonplus.

Source: https://en.wiktionary.org/wiki/fickle