Mastigophoran and Protozoan

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

Protozoan and mastigophoran are semantically related. In some cases you can use "Protozoan" instead a noun "Mastigophoran".

Protozoan noun - Any of diverse minute acellular or unicellular organisms usually nonphotosynthetic.

Mastigophoran and protozoan are semantically related. Sometimes you can replace term "Mastigophoran" with "Protozoan", this nouns are similar.