horribilis

Horribilis is a Latin adjective meaning “horrible,” “dreadful,” or “formidable.” In scientific naming, the term is commonly used as a species epithet within binomial nomenclature to convey that the describer regarded the organism as striking, fearsome, or notable in appearance or behavior. The form derives from the root horr-, related to shuddering or causing horror, plus the suffix -ibilis, meaning “able to be.”

In taxonomy, horribilis is typically treated as a descriptive epithet that must agree with the genus name in gender. As with many Latin adjectives, its exact form can vary to harmonize with the noun it modifies, but it is often retained as a recognizable epithet across different taxa. The epithet is chosen by the taxonomist describing the species and does not imply a moral judgment or any actual danger to humans.

The usage of horribilis appears across a range of organisms in taxonomic literature, including animals, plants, and fossil taxa. It is one of many Latin descriptors used to highlight distinctive features, such as conspicuous morphology, size, coloration, or other traits that elicited a strong impression during discovery or study. Like other epithets, horribilis is primarily a conventional label rooted in tradition and Latin grammar rather than a precise descriptive standard.

See also: Latin in scientific naming, binomial nomenclature, species epithet.