\Stip"ule\, n. [L. stipula a stalk, stem, straw: cf. F.
stipule. Cf. {Stubble}.] (Bot.)
An appendage at the base of petioles or leaves, usually
somewhat resembling a small leaf in texture and appearance.
Biology Dictionary
Definition:
One of a pair of appendages at the bases of leaves in many dicotyledons.
Webster's 1913 Dictionary