A virucide (pronounced /ˈvī-rə-ˌsīd/ and alternatively spelled 'viricide' and 'viruscide') is an agent (physical or chemical) that deactivates or destroys viruses.This differs from an antiviral drug which inhibits the development of the virus. virucide (pronounced /ˈvī-rə-ˌsīd/ and alternatively spelled 'viricide' and 'viruscide') is an agent (physical or chemical) that deactivates or destroys viruses.