Smallpox and Variola minor

Smallpox noun - A highly contagious viral disease characterized by fever and weakness and skin eruption with pustules that form scabs that slough off leaving scars.

Variola minor and smallpox are semantically related. In some cases you can replace phrase "Variola minor" with "Smallpox", this terms are similar.

Variola minor noun - A mild form of smallpox caused by a less virulent form of the virus.

Smallpox and variola minor are semantically related. You can use "Smallpox" instead a noun phrase "Variola minor".