flagellated_protozoan has definitions from the field of biology
1
[ noun ] (biology) usually nonphotosynthetic free-living protozoan with whiplike appendages; some pathogens of humans and other animals

Used in print

(Ross E. McKinney and Howard Edde, "Aerated...)

Initially , the flagellated_protozoa predominated , but they soon gave_way to the free_swimming ciliated_protozoa .

*