Fon"ta*nel` (?), 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.
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.
⇒ 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.
© Webster 1913.