infective

The word 'infective' is built upon the Latin verb inficere, meaning "to dip in, stain, taint, or corrupt". This verb itself is a compound of the prefix in- (in, into) and the root facere (to make, to do). The literal sense was "to put something into" or "to work something in," which evolved into the idea of introducing a contaminating agent. The suffix -ivus was added to form the adjective, describing the property of being able to "make something enter" a state of disease. Thus, the modern medical meaning of "capable of causing infection" directly follows the ancient logic of an agent that "works in" or "introduces" a pathological condition into a host.