Kaffir pox and Smallpox

Kaffir pox noun - A mild form of smallpox caused by a less virulent form of the virus.

Smallpox and Kaffir pox are semantically related. In some cases you can use "Smallpox" instead a noun phrase "Kaffir pox".

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.

Kaffir pox and smallpox are semantically related. Sometimes you can replace phrase "Kaffir pox" with "Smallpox", this terms are similar.