Definitions of eccentric:

• noun:   a person with an unusual or odd personality
• noun:   a person of a specified kind (usually with many eccentricities)

  Example: "A friendly eccentric"

• adjective:   not having a common center; not concentric

  Example: "Eccentric circles"

• adjective:   conspicuously or grossly unconventional or unusual

  Example: "Famed for his eccentric spelling"