Definitions

1. adjective

relating to or containing infusoria, especially diatoms or other algae that form a sedimentary deposit, especially in water or soil

“The infusorial sediment at the bottom of the lake was a result of years of algae accumulation.”

2. noun

a person or thing that infusoriums or infusoria

“The scientist studied the infusorial organisms in the microscope.”

3. noun

the microscopic organisms themselves, especially diatoms or other algae

“The infusorial life in the sample was abundant and diverse.”