Cam"bi*um (?), n. [LL. cambium exchange, fr. L. cambire to exchange. It was supposed that cambium was sap changing into wood.] 1. (Bot.) 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.) A fancied nutritive juice, formerly supposed to originate in the blood, to repair losses of the system, and to promote its increase. Dunglison.