: an infectious disease of birds caused by a bacterium (Chlamydia psittaci synonym Chlamydophila psittaci), marked by diarrhea and wasting, and transmissible to humans in whom it occurs as a flu-like illness often accompanied by pneumonia
Recent Examples on the WebIn 1929 and 1930, there was a global outbreak of psittacosis, an infectious disease that can be transferred from birds to humans. Brigit Katz, Smithsonian, 12 Dec. 2019 The birds also could transmit diseases to humans, such as psittacosis (parrot fever), avian flu and salmonella, The Guardian reported.Fox News, 9 Oct. 2019