Webster's Revised Unabridged Dictionary · 1913

Liber

Liber (lī"bẽr) , noun

[L. See Libel.]

(Botany) The inner bark of plants, lying next to the wood. It usually contains a large proportion of woody, fibrous cells, and is, therefore, the part from which the fiber of the plant is obtained, as that of hemp, etc.
Collocations (1)
Liber cells , elongated woody cells found in the liber.