Hardy
Middle English (in the sense ‘bold, daring’): from Old French hardi, past participle of hardir ‘become bold’, of Germanic origin; related to hard.
wiktionary
From Middle English hardy, hardi, from Old French hardi(“hardy, daring, stout, bold”). Old French hardi is usually regarded as the past participle of hardir("to harden, be bold, make bold"; compare Occitan ardir, Italian ardire), from Frankish *hardijan; but it may also have come directly from Frankish *hardi, a secondary form of Frankish *hard (compare Old High German harti, herti, secondary forms of Old High German hart(“hard”)); or even yet from Frankish *hardig (compare Middle Low German herdich(“persevering”), Old Danish hærdig, Norwegian herdig, Swedish härdig(“vigorous, courageous”)). Cognate with hard. May have at some point also been surface analysed as hard + -y.
etymonline
hardy (adj.)
c. 1200, "bold, daring, fearless," also "presumptuous, audacious," from Old French hardi "bold, brave, courageous; confident, presumptuous," from past participle of hardir "to harden, be or make bold," from Frankish *hardjan "to make hard" (source also of Old Frisian herda, Old High German herten, Old Norse herða, Gothic gahardjan "make hard"), from Proto-Germanic *hardu- (from PIE root *kar- "hard"). Sense influenced by English hard. Of plants, "able to survive in the open year-round," 1660s. Related: Hardily; hardiness. Hardhede "physical hardiness" is attested from early 15c.
