The Collaborative International Dictionary of English v.0.48:

Varioloid \Va"ri*o*loid\ (?; 277), a. [Variola + -oid: cf. F.
   variolo["i]de.] (Med.)
   Resembling smallpox; pertaining to the disease called
   varioloid.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Varioloid \Va"ri*o*loid\, n. [Cf. F. variolo["i]de. See
   Varioloid, a.] (Med.)
   The smallpox as modified by previous inoculation or
   vaccination.
   [1913 Webster]

   Note: It is almost always a milder disease than smallpox, and
         this circumstance, with its shorter duration, exhibits
         the salutary effects of previous vaccination or
         inoculation. --Dunglison.
         [1913 Webster]