cetacean

This term is primarily used in scientific, biological, or academic contexts to categorize a specific group of marine mammals. It carries a clinical and precise tone, distinguishing these animals from other marine life like fish or pinnipeds by emphasizing their evolutionary lineage and physiological traits.

When used as a noun, it refers to the animal itself, while the adjective form describes attributes such as anatomy or behavior. Because it is a technical classification, it is rarely encountered in casual conversation unless the speaker is discussing marine biology or conservation efforts.