noun Date: circa 1944 any of a group of pneumonias (as Q fever and psittacosis) caused especially by viruses, mycoplasmas, rickettsias, and chlamydias
PRIMARY ATYPICAL PNEUMONIA
Meaning of PRIMARY ATYPICAL PNEUMONIA in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012