Fontanel /(?)/

Fon·ta·nel

Fontanel

n.
  1. An issue or artificial ulcer for the discharge of humors from the body. (Med.) [Obs.]
  2. 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. (Anat.)