Emily Dickinson Lexicon

FIS'SURE, n. [fish'ure; Fr. from L. fissura, from findo, to split.]

1. A cleft; a narrow chasm made by the parting of any substance; a longitudinal opening; as, the fissure of a rock.
2. In surgery, a crack or slit in a bone, either transversely or longitudinally, by means of external force. Encyc.
3. In anatomy, a deep, narrow sulcus, or depression, dividing the anterior and middle lobes of the cerebrum on each side. Coxe.