common knowledgenoun

• 1

  That which is known by most people, and thus cannot reasonably be contested.

  • A limited liability company is not subtle, Mrs Straithwaite. This one knows that you have insured a five-thousand-pound pearl necklace with it, and when it becomes a matter of common knowledge that you have had one answering to that description stolen, it jumps to the conclusion that they are one and the same.
• 2

  computingengineeringgame-theoryA special kind of knowledge for a group of agents, such that when all the agents in a group G know p, they all know that they know p, they all know that they all know that they know p, and so on ad infinitum.