nounpl. -·siae· or -·sias
any of several families (esp. Rickettsiaceae) of Gram-negative bacteria that are the causative agents of certain diseases, as typhus or Rocky Mountain spotted fever: they are transmitted to animals and humans by the bite of certain lice, ticks, etc. in whose bodies they live as parasites
Origin of rickettsiaModL, after H. T. Ricketts (1871-1910), United States pathologist + -ia
Any of various bacteria of the genus Rickettsia, carried as parasites by many ticks, fleas, and lice, that cause diseases such as typhus and Rocky Mountain spotted fever in humans.
Origin of rickettsiaNew Latin Rickettsia genus name after Howard Taylor Ricketts (1871-1910), American pathologist
(plural rickettsias or rickettsiae)
From Rickettsia (genus name)