Fissure \fis"sure\, n. [L. fissura, fr. findere, fissum, to cleave, split; akin to E. bite: cf. F. fissure.]

1. A narrow opening, made by the parting of any substance; a cleft; as, the fissure of a rock
2. A long narrow depression in a surface [syn: crevice, cranny, crack, chap]
3. A long narrow opening [syn: crack, cleft, crevice, scissure]
4. (anatomy) a long narrow slit or groove that divides an organ into lobes; the furrows or clefts by which the surface of the cerebrum is divided; esp., the furrows first formed by the infolding of the whole wall of the cerebrum
5. (Mining), a crack in the earth's surface filled with mineral matter. --Raymond

Fissure \fis"sure\, v. t