1. A source of information, supply, or origin that has been identified, verified, or is recognized
The journalist cited a known source for the story.
A jornalista citou uma fonte conhecida para a história.
2. In intelligence or security contexts, a person or entity whose identity and reliability have been established
The agent received intelligence from a known source within the organization.
O agente recebeu inteligência de uma fonte conhecida dentro da organização.
3. In academic or research contexts, a documented reference that can be identified and consulted
All claims must be supported by known sources.
Todas as afirmações devem ser apoiadas por fontes conhecidas.