Learner's definition of HARDY. 1. : able to live through difficult conditions (such as a cold winter or a drought). a hardy rose. the hardiest plants/animals. [+] more examples [-] hide examples [+] Example sentences [-] Hide examples. 2. : strong and able to accept difficult or unpleasant conditions. Most of the soldiers were hardy young men. Hardy fans stuck with the team through good times and bad. Only the hardiest pilgrims made the journey. [+] more examples [-] hide examples [+] Example sentences [-] Hide examples.