easily spread; "fear is exceedingly infectious; children catch it from their elders"- Bertrand Russell
caused by infection or capable of causing infection; "viruses and other infective agents"; "a carrier remains infective without himself showing signs of the disease"
of or relating to infection; "infectious hospital"; "infectious disease"
(mathematics, logic) such that the arguments or roles can be interchanged; "the arguments of the symmetric relation, `is a sister of,' are interchangeable"