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"The Quatrefoil is a piercing or panel divided by cusps or foliations into four leaves, or more correctly the leaf-shaped figure formed by the cusps. The name is also given to flowers and leaves of a similar form carved as ornaments on moldings, etc. It differs from the cinquefoil only in the number of cusps."—(Charles Leonard-Stuart, 1911)

Quatrefoil

"The Quatrefoil is a piercing or panel divided by cusps or foliations into four leaves, or more correctly…