Definitions of supple:

• verb:   make pliant and flexible

  Example: "These boots are not yet suppled by frequent use"

• adjective:   (used of persons' bodies) capable of moving or bending freely
• adjective:   (used of e.g. personality traits) readily adaptable

  Example: "A supple mind"

• adjective:   gracefully slender; moving and bending with ease
• name:  A surname (very rare: popularity rank in the U.S.: #25996)