quatrefoil

From Old French quatrefoil, from quatre (“four”) + foil (“leaf”).

quatrefoil (plural quatrefoils)

1. (architecture) A symmetrical shape that forms the overall outline of four partially-overlapping circles of the same diameter.
2. (heraldry) A stylized flower or leaf with four lobes.

• 1988, Alan Hollinghurst, The Swimming Pool Library, Penguin Books, paperback edition, page 142

  It was a narrow, gravelled island we had to lie on, guarded by glazed brick chimneys and, running along the sides, a prickly little gothic fence of iron finials and terracotta quatrefoils.

• trefoil
• cinquefoil
• sexfoil
• octofoil
• multifoil
• polyfoil

• quaterfoil