n :  a genus (the type of the family Trichomonadidae) of polymastigote parasitic flagellated protozoans that have four anterior flagella and another at the margin of an undulating membrane or in some classifications also include forms with three or five anterior flagella and that are parasites of the alimentary or genitourinary tracts of numerous vertebrate and invertebrate hosts including one (T. vaginalis) causing human vaginitis .
 
 
 
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