What does "fontanel" mean?

Fontanel: (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. Note: 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.