Mastigophoran and Protozoon

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

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

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

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