Antiviral

Etymology

A modern compound of Greek "anti-" (against) and "virus" (Latin for "poison" or "slimy liquid"). The word is young because the concept is: viruses were only confirmed as distinct infectious agents in the late 19th century, and drugs against them arrived decades after antibiotics.

adjective · /an-tee-VY-rul/
Acting to stop or slow the replication of viruses.
What it names
A distinct class of drugs that many people wrongly expect their antibiotics to cover.
Example
The doctor explained that her flu needed an antiviral, and that the antibiotics she demanded would do nothing at all.
Related idea
An antiviral targets viruses; an antibiotic targets bacteria — which is why antibiotics are useless against a cold or flu, and overusing them for viral illness breeds resistance for nothing.