noun Botany.

increased growth along the lower surface of a plant or plant part, causing it to bend upward.

Origin of hyponasty

1870–75; hypo- + Greek nast(ós) pressed close, compact + -y3
Related formshy·po·nas·tic, adjectivehy·po·nas·ti·cal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for hyponasty



increased growth of the lower surface of a plant part, resulting in an upward bending of the partCompare epinasty
Derived Formshyponastic, adjectivehyponastically, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012