CAMBIUM
cambium
(noun) the inner layer of the periosteum
cambium
(noun) a formative one-cell layer of tissue between xylem and phloem in most vascular plants that is responsible for secondary growth
Source: WordNet® 3.1
Etymology
Noun
cambium (plural cambiums or cambia)
(botany) A layer of cells between the xylem and the phloem that is responsible for the secondary growth of roots and stems.
(anatomy) Periosteum, a membrane that covers the outer surface of bones
(obsolete) One of the humours formerly believed to nourish the bodily organs.
Source: Wiktionary
Cam"bi*um, n. Etym: [LL. cambium exchange, fr. L. cambire to
exchange. It was supposed that cambium was sap changing into wood.]
1. (Bot.)
Definition: A series of formative cells lying outside of the wood proper
and inside of the inner bark. The growth of new wood takes place in
the cambium, which is very soft.
2. (Med.)
Definition: A fancied nutritive juice, formerly supposed to orgiginate in
the blood, to repair losses of the system, and to promote its
increase. Dunglison.
Source: Webster’s Unabridged Dictionary 1913 Edition