- fontanelle, fontanel, soft spot - any membranous gap between the bones of the cranium in an infant or fetus
--1 is a kind of orifice, opening, porta
--1 is a part of cranium, braincase, brainpan; child's body
--1 has particulars:anterior fontanelle; sphenoid fontanelle, sphenoid fontanel, sphenoidal fontanelle, sphenoidal fontanel