From the German element “hedu,” meaning “battle” or “war.” But your little Hedy will be a peaceful sort … until it’s time to force her into the bathtub after a long day of playing outside, that is.
Hedy is already a nickname for longer names like Hedwig, so it's hard to shorten it any further.
Famous people named Hedy:
Actress Hedy Lamarr.
Actress Hedy Lamarr's birth name was Hedwig, like Harry Potter's owl. Hedy can also be a nickname for Heather.