Trefoil

[Sarah]

Any plant of the genus Trifolium, which includes the whiteclover, red clover, etc.; -- less properly, applied also to thenonesuch, or black medic. See Clover, and Medic.

[Sarah]

yummy girl scout shortbread cookies

[Gregory]

[Something] with [3-way] [symmetry].

[Michiko]

A small European plant of the pea family, with yellow flowers and three-lobed clover-like leaves.