*fontanel*

n. [ F. fontanelle, prop., a little fountain, fr. fontaine fountain. See Fountain. ] 1. (Med.) An issue or artificial ulcer for the discharge of humors from the body.[ Obs. ] Wiseman. [ 1913 Webster ]

2. (Anat.) One of the membranous intervals between the incompleted angles of the parietal and neighboring bones of a fetal or young skull; -- so called because it exhibits a rhythmical pulsation. [ 1913 Webster ]

☞ In the human fetus 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. [ 1913 Webster ]