Dinoflagellate and Flagellate

Dinoflagellate noun - Chiefly marine protozoa having two flagella; a chief constituent of plankton.

Flagellate and dinoflagellate are semantically related. In some cases you can use "Flagellate" instead a noun "Dinoflagellate".

Flagellate noun - A usually nonphotosynthetic free-living protozoan with whiplike appendages; some are pathogens of humans and other animals.

Dinoflagellate and flagellate are semantically related. Sometimes you can replace term "Dinoflagellate" with "Flagellate", this nouns are similar.