Definition

1. Noun:
   • Any member of the subclass Infusoria: An "infusorian" is a microscopic, single-celled organism, typically a ciliate protozoan, belonging to the now largely historical taxonomic subclass Infusoria. These organisms are often found in infusions of decaying organic matter.

Usage

• The term "infusorian" is primarily used in historical or specialized biological contexts to refer to certain microscopic aquatic organisms, especially ciliates.
• It is a countable noun.

Examples

• Under the microscope, the water sample teemed with various infusorians.
• Early microbiologists studied infusorians to understand microscopic life.

Advanced Usage

• The subclass Infusoria was named because these organisms were commonly observed in infusions (e.g., hay infusions). While the taxonomic grouping is outdated, the term "infusorian" persists in historical literature.

Variants and Related Words

• Infusoria (n, plural): The former taxonomic subclass name.
  • The study of Infusoria was pivotal in the development of protozoology.

Synonyms

• Ciliate: A more modern and precise term for many organisms once classified as infusorians.
• Protozoan: A broader term for single-celled eukaryotic organisms, which includes infusorians.

Notes on Meaning

• The core meaning refers to a member of the specific historical group Infusoria. It does not refer to all microorganisms found in infusions, only to those ciliate protozoans originally classified within this group. The term is largely obsolete in modern scientific classification.

Noun

1. any member of the subclass Infusoria