Which term best describes the majority of protozoa

Single - celled eukaryotes

Explanation:

The best term to describe majority of protozoans is that they are single - celled eukaryotic organisms.

They are often called one-celled animal.

Protozoans are micro-organisms that are made up single cells. They are able to carryout different life functions. Some are free living whereas others are parasitic causing diseases in higher animals. They are found in a broad range of habitats in nature.