adj. (hardier, hardiest) 1 robust; capable of enduring difficult conditions. 2 (of a plant) able to grow in the open air all the year. hardy annual 1 an annual plant that may be sown in the open. 2 joc. a subject that comes up at regular intervals. hardily adv. hardiness n.
[ ME f. OF hardi past part. of hardir become bold, f. Gmc, rel. to HARD ]