What is the meaning of the word "paper"?

Definitions:

a business firm that publishes newspapers noun
- Murdoch owns many newspapers
a medium for written communication noun
- the notion of an office running without paper is absurd
a scholarly article describing the results of observations or stating hypotheses noun
- The chemist has written many scientific papers.
cover with paper verb
- paper the box
the physical object that is the product of a newspaper publisher noun
- When it began to rain I covered my head with the paper.