fontanel
/ˌfɑntəˈnɛl/
noun
- A soft spot on a baby's head where the skull bones have not yet joined together.
- Parents are often told not to press on the fontanel because it is delicate.
- The fontanel usually closes completely by the time a child is two years old.
- The doctor gently felt the baby's fontanel to check for signs of dehydration.