Internus

Part of speech: adjective

Definitions

1. A term used in anatomy to refer to structures located on the inner side of an organ or body part
2. designating muscles or tissues that are situated within a particular cavity or space
3. describing elements that are not externally visible but play a role in bodily functions or organization

Etymology: "Internus" is a Latin adjective meaning "internal" or "inward," built from the preposition and adverb "intus," meaning "within," plus the adjectival suffix "-nus." Latin "intus" itself appears to combine "in" with a locative ending, so the word literally points to the inside of something. In Latin it was used broadly for things on the inner side, but it is in anatomy that it found its lasting role. Anatomists in English and other modern languages drew on this Latin form for structures that lie within a body part or organ, such as the internal carotid artery or the internal capsule of the brain. The sense "lying within cavities" reflects that technical usage: the adjective describes parts tucked inside a hollow space rather than on its surface. Because it is a Latin form adopted for scientific description, it is best understood as a classical coinage in modern anatomy rather than a word from everyday ancient speech.

Synonyms: internal, inner, inside

Antonyms: external, outer, outside