animalcule

As nouns the difference between unicellular and animalcule

is that unicellular is a single-celled organism; a unicell while animalcule is a minute or microscopic animal or protozoan.

As an adjective unicellular

is describing any microorganism that has a single cell.

As nouns the difference between animalcule and microbe

is that animalcule is a minute or microscopic animal or protozoan while microbe is any microorganism, but specially said of those microorganisms which are harmful types of bacteria.

As nouns the difference between animalcule and animalculism

is that animalcule is a minute or microscopic animal or protozoan while animalculism is a theory seeking to explain certain physiological and pathological phenomena in terms of animalcules.