fontanelle or fontanel /fon-tə-nelˈ/

1. A membrane-covered gap between the immature parietal bones in the skull of a fetus or infant
2. An opening for discharge (medicine)

• self-sterility
• self-studies
• self-study
• self-styled
• self-subdued
• self-substantial
• Sinic
• sinical
• sinicise
• sinicised
• sinicises
• sinicising
• Sinicism
• sinicize
• sinicized
• sinicizes
• sinicizing
• sining
• sinister
• sinisterities
• sinisterity
• sinisterly
• sinisterness
• sinisterwise
• sinistral