Intimae

Part of speech: noun

Definitions

1. The innermost layers or membranes of an organ or structure, especially the innermost lining of arteries or veins; the deepest or most essential parts of something; a close or intimate association with someone or something
2. The deepest interior membrane or lining found within biological structures like blood vessels; the core or most private aspect of a subject or entity; a personal and confidential relationship or connection
3. The internal lining forming the closest layer inside arteries or certain organs; the fundamental and central components of a system or concept; a deeply personal or confidential interaction or bond

Etymology: "Intimae" is the plural of "intima", a noun borrowed from Latin "intima", the feminine form of "intimus", meaning "innermost". The Latin adjective is a superlative built on "intus", "within", so the core idea is simply what lies furthest inside. English took the Latin word in its anatomical sense, and "intima" now names the innermost layer of an artery or vein, the lining that touches the blood. Anatomists use the plural when they refer to several such linings or membranes at once, which is why the form you see here is the one in use. From that physical sense the broader meanings grew: the deepest or most essential part of something, and by extension a close association with a person or thing. The word stays tied to its Latin root's sense of depth.

Synonyms: intima, inner layer