colicin
noun
co·li·cin ˈkō-lə-sən 
variants or less commonly colicine
ˈkō-lə-ˌsēn
: any of various antibacterial substances produced by strains of intestinal bacteria (as of E. coli)
Word History
Etymology
French colicine, from col- + -cine (as in streptomycine streptomycin)
First Known Use
1946, in the meaning defined above
Medical Definition
colicin
noun
co·li·cin ˈkō-lə-sən
variants also colicine
-ˌsēn
: any of various antibacterial proteins that are produced by some strains of intestinal bacteria (as E. coli) having a specific plasmid and that often act to inhibit macromolecular synthesis in related strains