'Midrib' definitions:

Definition of 'midrib'

From: WordNet
noun
The vein in the center of a leaf [syn: midrib, midvein]

Definition of 'Midrib'

From: GCIDE
  • Midrib \Mid"rib`\, n. (Bot.) A continuation of the petiole, extending from the base to the apex of the lamina of a leaf. [1913 Webster]