What is the meaning of skeleton?

noun

• Something reduced to its minimal form.
  • usage: "the battalion was a mere skeleton of its former self"; "the bare skeleton of a novel"
• A scandal that is kept secret.
  • usage: "there must be a skeleton somewhere in that family's closet"
  • synonyms: skeleton in the closet, skeleton in the cupboard
• The hard structure (bones and cartilages) that provides a frame for the body of an animal.
  • synonyms: skeletal system, frame, systema skeletale
• The internal supporting structure that gives an artifact its shape.
  • usage: "the building has a steel skeleton"
  • synonyms: skeletal frame, frame, underframe