contagium

noun

con·​ta·​gium kən-ˈtā-j(ē-)əm 

plural contagia kən-ˈtā-j(ē-)ə 

: an agent capable of causing a communicable disease

Word History

Etymology

borrowed from Latin contāgium, variant of contāgiō "contact, contagion"

First Known Use

1870, in the meaning defined above

Medical Definition

contagium

noun

con·​ta·​gium kən-ˈtā-j(ē-)əm 

plural contagia -j(ē-)ə 

: a virus or living organism capable of causing a communicable disease