... are known as Girl Scouts in the United States of America and some other countries. The organisation's official name is the World Association of Girl Guides and Girl Scouts (WAGGGS).
In botany, 'trefoil' is an alternative name for clover – after its triple–lobed leaf, which the Girl Guides' symbol represents. In architecture, a trefoil is an ornament composed of three lobes, divided by cusps, radiating from a common centre. (A cusp is a pair of curves, tangent to the real or imaginary line defining the area decorated, and meeting at a point within the area.)
Dictionary.com gives "such a figure used by the Girl Scouts as its official emblem" as one definition for trefoil.
© Haydn Thompson 2022