Trefoil (noun)

1. A three-lobed leaf or flower, especially a clover.
2. An architectural or heraldic ornament with three curves or loops, usually interlaced.

Origin:

From middle english trefoil, from old french trefle, from latin trifolium, from tri- ("three") + folium ("leaf").

Examples:

1. The meadow was covered with trefoil.
2. The trefoil symbol is commonly used as a logo for sports teams.
3. She made a trefoil knot to fasten the ropes.
4. The trefoil arches of the Gothic cathedral were a beautiful sight.
5. He had a trefoil tattoo on his arm.