The Collaborative International Dictionary
Contagiousness
Contagiousness \Con*ta"gious*ness\, n. Quality of being contagious. [1913 Webster] ||
Wiktionary
contagiousness
n. The state or condition of being contagious.
Usage examples of "contagiousness".
If it were something from the labs, it wouldn't be a common-cold virus, tailored by natural selection for maximum contagiousness, no matter what symptoms it produced.