Obliquus

Obliquus is a Latin adjective meaning oblique or slanting. In scientific terminology, the form is used as a descriptive epithet to denote oblique orientation or position of a structure, rather than to indicate a taxonomic rank.

In anatomy, several muscles carry the epithet obliquus because their fibers run at an oblique angle or because their action involves oblique movement. Common examples include the musculus obliquus externus abdominis (external oblique muscle of the abdomen) and the musculus obliquus internus abdominis (internal oblique muscle). The musculi obliquus oculi superior and musculus obliquus oculi inferior are the superior and inferior oblique muscles of the eye, involved in turning the eye. The hyoid and neck region also features oblique muscles such as musculus obliquus capitis inferior and musculus obliquus capitis superior, named for their oblique orientations relative to the skull.

Beyond anatomy, obliquus appears in botanical and zoological nomenclature as a descriptive epithet in species names to indicate oblique features of leaves, growth habit, or other morphological traits. It does not designate a taxon by itself but signals a characteristic similar across different groups.

In linguistics and grammar, the related term oblique is used to describe non-nominative cases and non-primary forms; the English word derives from the same Latin root, obliquus. Overall, obliquus serves as a historical descriptive descriptor across disciplines to indicate slanting or oblique orientation. See also oblique and related terms.