anguillid

This term is primarily used in ichthyology and biological taxonomy to distinguish true eels from other eel-like fish, such as moray eels or lungfish. It carries a clinical, scientific tone and is rarely encountered in casual conversation, where the general term eel is preferred.

As a noun, it refers to a specific biological entity within the Anguillidae family. When used as an adjective, it describes anatomical features or behavioral patterns, such as the catadromous migration cycle, that are specific to these organisms.