Meaning

originSee harrow or haro. The claim has been made that the word is from Old French haro, harou, from two words, "Ha" and "Rollo", referring to Duke Rollo of Normandy; his name became well known as a cry for justice and was later shortened to "Haro." -"The Little Duke", Charlotte Young, 1955

Etymology from Wiktionary, CC BY-SA 3.0