Orbicularis

Part of speech: noun

Pronunciation: /ɔːˌbɪk.jʊˈlɑː.ɹɪs/

Definitions

1. A circular muscle that encircles openings in the body, facilitating the control of functions such as movement and expression
2. A muscle group that forms a circular shape around structures like the mouth and eyes, regulating their opening and closing
3. A ring-shaped muscle that encircles openings in the body and controls their movement

Etymology: Anatomists gave this muscle its name by shortening a longer Latin phrase. The full New Latin term was "musculus orbicularis", meaning "circular muscle", and English took the adjective-turned-noun "orbicularis" as a shorthand for the whole thing. The muscle it names rings the eye or the mouth, and its circular fibres are what close the lids or purse the lips. The Latin root "orbis" means "circle" or "disk", the same root behind words like "orbit" and "orb". The word is a doublet of "orbicular", the adjective meaning round or circular. Both descend from the Latin "orbicularis", but "orbicular" came into English as a general descriptive term, while "orbicularis" was borrowed specifically as an anatomical label. The two forms therefore share a source yet took different paths into the language.