rəˌketsēˈāsēˌē, (ˌ)riˌk- noun plural
Usage: capitalized
Etymology: New Latin, from Rickettsia, type genus + -aceae
: a family of microorganisms (order Rickettsiales) resembling bacteria and being typically inhabitants of arthropod tissues but capable in some cases of causing serious disease in man and other vertebrates — compare cowdria , rickettsia