Definitions of changeable:

• adjective:   subject to change

  Example: "A changeable climate"

• adjective:   such that alteration is possible; having a marked tendency to change

  Example: "Changeable behavior"

• adjective:   varying in color when seen in different lights or from different angles

  Example: "Changeable taffeta"

• adjective:   capable of or tending to change in form or quality or nature