Main Entry: rick·ett·sia

Pronunciation: \ri-ˈket-sē-ə\

Function: noun

1 capitalized : the type genus of the family Rickettsiaceae comprising rod-shaped, coccoid, or diplococcus-shaped often pleomorphic bacteria that live intracellularly in biting arthropods (as lice or ticks) and when transmitted to humans by the bite of an arthropod host cause a number of serious diseases (as Rocky Mountain spotted fever and typhus)
2 plural rick·ett·si·ae \-ˌē\ also rick·ett·sias or rick·ett·sia : any bacterium of the order Rickettsiales and especially of the family Rickettsiaceae