Definitions

1. adjective

relating to or resembling infusoria, especially in being unicellular and flagellate

“The infusory organisms were studied in a petri dish under a microscope.”

2. noun

a member of a class of unicellular flagellate eukaryotes, especially those that are aquatic and are found in water and in damp places

“The infusory organisms were studied in a petri dish under a microscope.”