her·pe·tom·o·nas \-nəs, -ˌnas\noun Etymology: New Latin, from herpet- + -monas 1.capitalized: a genus of flagellates of the family Trypanosomatidae that are parasites of the gut of insects 2.-es: any flagellate of the genus Herpetomonas; also: any member of the Trypanosomatidae that appears to have two flagella due to precocious duplication of the locomotor apparatus