Process of rendering something inactive. For viruses, the efficacy of disinfectants is termed "inactivation of viruses", as they are "vagabond genes" and need host cells to propagate. They do not have their own metabolism.
In disinfectant testing, there is the common term "inactivation of disinfectants". This term is increasingly replaced by "neutralisation". Here, the term "inactivation" is not used in the sense of killing microorganisms, but in the sense of neutralising the methodological residual effect of the disinfectant.