harrow

Concise Oxford English Dictionary © 2008 Oxford University Press:
harrow/ˈharəʊ/

▶noun an implement consisting of a heavy frame set with teeth or tines which is dragged over ploughed land to break up or spread the soil. ▶verb

• 1 draw a harrow over.

• 2 (usu. as adj. harrowing) cause distress to: a harrowing film about racism.

– derivatives
harrower noun,
harrowingly adverb.

– origin ME: from ON herfi.