jagged adj.

mid-15c., "having notches," from verb jaggen (c. 1400) "to pierce, slash, cut; to notch or nick; cut or tear unevenly," a Scottish and northern English word of unknown origin, related to jag (n.2). Originally of garments with regular "toothed" edges; meaning "with the edge irregularly cut" is from 1570s. Related: Jaggedly; jaggedness.