What is "microbicide"

Microbicide \Mi*crob"i*cide\, n. [Microbe + L. caedere to kill.] (Biol.) Any agent detrimental to, or destructive of, the life of microbes or bacterial organisms.

n. Any substance that is harmful to and kills microorganisms.

A microbicide is any biocidal compound or substance whose purpose is to reduce the infectivity of microbes, such as viruses or bacteria. One example is wood tar.