The place where two barrel vaults intersect in architecture is called a groin vault. This occurs when two barrel vaults cross at right angles, creating a distinct intersection known as the groin or cross vault

. The groin vault is formed by the edges or "groins" created by the intersection of the curved surfaces of the two barrel vaults. In summary:

• Two barrel vaults intersecting at right angles form a groin vault.
• The intersection lines are called groins.
• This architectural feature improves structural integrity by concentrating forces to the corners

This term is commonly used in architectural contexts and appears frequently as a crossword answer for clues about intersecting barrel vaults