quat·re·foil 
(kătər-foil′, kătrə-)
(kătər-foil′, kătrə-)n.
1. A representation of a flower with four petals or a leaf with four leaflets, especially in heraldry.
2. Architecture Tracery or an ornament with four foils or lobes.
[Middle English quaterfoile : Old French quatre, four; see QUATRAIN + Old French foil, leaf; see FOIL2.]