harrow (n.) Look up harrow at Dictionary.com
agricultural implement, heavy wooden rake, c. 1300, haru, probably from an unrecorded Old English *hearwa, apparently related to Old Norse harfr "harrow," and perhaps connected with harvest (n.). Or possibly from hergian (see harry (v.)).
harrow (v.1) Look up harrow at Dictionary.com
"to drag a harrow over, break or tear with a harrow," c. 1300, from harrow (n.). In the figurative sense of "wound the feelings, distress greatly" it is first attested c. 1600 in Shakespeare. Related: Harrowed; harrowing.
harrow (v.2) Look up harrow at Dictionary.com
"to ravage, despoil," especially in harrowing of Hell in Christian theology, early 14c., from Old English hergian "to ravage, plunder; seize, capture" (see harry (v.)). Related: Harrowed; harrowing.