spina

Spina is a term with multiple meanings across languages and disciplines. From Latin spina, meaning spine or thorn, it functions as a root in many Romance languages, including Italian. In biology and medicine, spina commonly denotes a spine-like projection. In anatomy, it refers to a spiny projection on a bone, especially the spinous process of a vertebra, and more generally to the backbone. In botany and plant anatomy, spina denotes a plant spine or thorn, such as the spines on cacti or other succulents. The word is also used in zoology to describe spines on shells or exoskeletons.

In medical terminology, the root appears in phrases related to the spine, most famously spina bifida, a neural tube defect affecting spinal development. Spina is used in various compound names describing spinal structures, pathology, or anatomical directions in classical Latin-based nomenclature.

Geography and culture also reflect the term. Spina is the name of several places, including the ancient Etruscan-Roman city of Spina on the Po delta in northern Italy, known from classical sources and archaeological remains. The toponym Spina appears in contemporary locations as well, illustrating how the word has migrated from a descriptive root to geographic names.