Definitions of flexible:

• adjective:   bending and snapping back readily without breaking
• adjective:   able to flex; able to bend easily

  Example: "Slim flexible birches"

• adjective:   extended meanings; capable of change

  Example: "A flexible character"

• adjective:   able to adjust readily to different conditions

  Example: "A flexible personality"

• adjective:   making or willing to make concessions