Definitions of skin:

• noun:   an outer surface (usually thin)

  Example: "The skin of an airplane"

• noun:   a bag serving as a container for liquids; it is made from the skin of an animal
• noun:   a natural protective covering of the body; site of the sense of touch

  Example: "Your skin is the largest organ of your body"

• noun:   a person's skin regarded as their life

  Example: "He tried to save his skin"

• noun:   the tissue forming the hard outer layer (of e.g. a fruit)
• noun:   the rind of a fruit or vegetable
• noun:   body covering of a living animal
• verb:   strip the skin off
• verb:   bruise, cut, or injure the skin or the surface of

  Example: "The boy skinned his knee when he fell"

• verb:   remove the bark of a tree
• verb:   strike against an object
• verb:   climb awkwardly, as if by scrambling