1. <medicine> An issue or artificial ulcer for the discharge of humors from the body.

2. <anatomy> One of the membranous intervals between the incompleted angles of the parietal and neighboring bones of a foetal or young skull; so called because it exhibits a rhythmical pulsation.

In the human foetus there are six fontanels, of which the anterior, or bregmatic, situated at the junction of the coronal and sagittal sutures, is much the largest, and remains open a considerable time after birth.

Origin: F. Fontanelle, prop, a little fountain, fr. Fontaine fountain. See Fountain.

(01 Mar 1998)