gib·ber·el·lin 
(jĭb′ə-rĕlĭn)
(jĭb′ə-rĕlĭn)n.
Any of several plant hormones, such as gibberellic acid, that stimulate stem elongation, seed germination, and other physiological processes.
[From New Latin Gibberella (fujikoroī), the fungus from which a gibberellin was first isolated, from Latin gibberella, feminine diminutive of gibber, hump (from the humplike shape of the genus's perithecia).]