A system detects and decodes semantic camouflage in natural language messages. The system is adapted to identify entities such as words or phrases in overt messages that are being used to disguise different and unrelated entities or concepts. The system automatically determines the semantic plausibility of the overt message and identifies entities that appear in implausible contexts. In addition, the system automatically estimates covert meanings for the entities identified in the overt message that appear in implausible contexts.