Undifferentiated tissue from which new cells are formed, as at the tip of a stem or root

Wiktionary Word definitions in Wiktionary
n. (context botany English) The plant tissue composed of totipotent cells that allows plant growth.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Meristem \Mer"i*stem\, n. [Gr. ? divisible.] (Bot.) A tissue of growing cells, or cells capable of further division.

Wikipedia Word definitions in Wikipedia
A meristem is the tissue in most plants containing undifferentiated cells ( meristematic cells ), found in zones of the plant where growth can take place. Meristematic cells give rise to various organs of the plant and keep the plant growing. The shoot ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"growing cellular tissues of plants," 1862, formed irregularly from Greek meristos "divided, divisible" (from merizein "to divide, distribute," from meros "a part, a share;" see merit (n.)) + ending from xylem , etc.

WordNet Word definitions in WordNet
n. undifferentiated tissue from which new cells are formed, as at the tip of a stem or root