1. A soft spot on a baby's skull where the bones have not yet fused together, allowing the head to compress during birth and the brain to grow.
Usage: Also spelled fontanel.; Commonly used in pediatrics and child development contexts.

Examples

• The doctor gently examined the baby's fontanelle during the newborn checkup.
• A bulging fontanelle can sometimes indicate increased pressure in the brain.
• Most fontanelles close completely by age two as the skull bones harden and fuse.
• Parents are often advised to be careful when touching a baby's fontanelle.
• The anterior fontanelle is the largest and most easily felt soft spot on an infant's head.