n, pl  -a*ses   :  infection with or disease caused by trichomonads: as  a  :  a human sexually transmitted disease occurring esp. as vaginitis with a persistent discharge and caused by a trichomonad (Trichomonas vaginalis) that may also invade the male urethra and bladder  b  :  a venereal disease of domestic cattle caused by a trichomonad (T. foetus) and marked by abortion and sterility  c  :  one or more diseases of various birds caused by trichomonads (esp. T. gallinae) and resembling blackhead - called also roup  .
 
 
 
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