dinoflagellate: chiefly marine protozoa having two flagella; a chief constituent of plankton
flagellate: a usually nonphotosynthetic free-living protozoan with whiplike appendages; some are pathogens of humans and other animals
pelagianism: the theological doctrine put forward by Pelagius which denied original sin and affirmed the ability of humans to be righteous; condemned as heresy by the Council of Ephesus in 431