greg·a·rine  (grěg'ə-rīn')  n. Any of various sporozoan protozoans of the order Gregarinida that are parasitic within the digestive tracts of various invertebrates including arthropods and annelids. adj. Of or belonging to the order Gregarinida. [From New Latin Gregārīna, type genus, from Latin gregārius, belonging to a flock; see gregarious.] greg'a·rin'i·an (-rĭn'ē-ən) adj. |