\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.
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.