Ornithonyssus
noun
Or·ni·thon·ys·sus
| \ ˌȯr-nə-ˈthän-ə-səs
, -thə-ˈnis-əs
\
, -thə-ˈnis-əs
\
Medical Definition of Ornithonyssus
: a genus of mites (family Macronyssidae) that are parasitic on vertebrates and include the rat mite (O. bacoti) and two serious pests (O. bursa and O. sylviarum) of domestic fowl