Hart
Old English heorot, heort, of Germanic origin; related to Dutch hert and German Hirsch .
wiktionary
From Middle English hert, from Old English heorot(“stag”), from Proto-Germanic *herutaz (compare Dutch hert, German Hirsch, Danish/Norwegian/Swedish hjort), from Pre-Germanic *kerudos, from Proto-Indo-European *ḱóru(“horn”).
See heart.
etymonline
hart (n.)
Middle English hert, from Old English heorot "hart, stag, male of the red deer," from Proto-Germanic *herutaz (source also of Old Saxon hirot, Old Frisian and Dutch hert "stag, deer," Old High German hiruz, Old Norse hjörtr, German Hirsch "deer, stag, hart"), perhaps from PIE *keru-, extended form of root *ker- (1) "horn; head." For vowel change, see marsh.
In later times, a male deer after its fifth year, when the crown antler has appeared. The female is a hind (n.).
