innominatus

Innominatus is a Latin adjective meaning nameless or unnamed. It derives from in- “not” and nomen “name,” with the suffix -atus forming an adjective. In English, related forms include innominate and innominatum, used in anatomy and historical contexts to denote something unnamed.

In anatomy, innominate is a common descriptor and noun. The innominate bone, also called os innominatum, refers to the hip bone formed by the fusing of the ilium, ischium, and pubis, and together with the sacrum constitutes part of the pelvic girdle. The term innominate artery is an older designation for the brachiocephalic trunk, the first major branch of the aortic arch; modern texts typically prefer brachiocephalic trunk. The general sense of innominate in anatomical terms is “not given a name,” which explains its use for structures that may be unnamed in a particular context.

In Latin literature and older scientific writing, innominatus may appear as an adjective modifying a noun to indicate that the author or work is unnamed, e.g., opus innominatum. In contemporary taxonomy, innominatus is rarely used as a formal epithet; most naming follows descriptive, commemorative, or otherwise informative epithets, or uses sp. for undetermined specimens.

See also: innominate, os innominatum, brachiocephalic trunk.