fissure
1. fis.sure \'fish-*r\ n 1: a narrow opening or crack of some length and depth usu. occurring from s ome breaking or parting 2: a separation or disagreement in thought or viewpoint : SCHISM 3a: a natural cleft between body parts or in the substance of an organ 3b: a break or lesion in tissue usu. at the junction of skin and mucous mem brane 2. fissure vt : to break into fissures : CLEAVE, CRACK, DIVIDE