trefoil

American  

[tree-foil, tref-oil] / ˈtri fɔɪl, ˈtrɛf ɔɪl /

noun

1. any of numerous plants belonging to the genus Trifolium, of the legume family, having usually digitate leaves of three leaflets and reddish, purple, yellow, or white flower heads, comprising the common clovers.

2. any of various similar plants.

3. Architecture. an ornament composed of three lobes, divided by cusps, radiating from a common center.

4. such an ornamental figure used by the Girl Scouts as its official emblem.

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adjective

1. of, relating to, or shaped like a trefoil.

trefoil British  

/ ˈtrɛfɔɪl /

noun

1. any of numerous leguminous plants of the temperate genus Trifolium , having leaves divided into three leaflets and dense heads of small white, yellow, red, or purple flowers

2. any of various related plants having leaves divided into three leaflets, such as bird's-foot trefoil

3. a leaf having three leaflets

4. architect an ornament in the form of three arcs arranged in a circle

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Other Word Forms

• trefoiled
  adjective

Etymology

Origin of trefoil

1350–1400; Middle English < Anglo-French trifoil < Latin trifolium triple leaf, the three-leaved plant, clover, equivalent to tri- tri- + folium leaf

Example Sentences

Nike have recently relaunched their T90 collection, and Adidas' 2026 World Cup away jerseys have the Adidas original Trefoil badge on the chest after 36 years, a re-interpretation of the classic '90s look.

From BBC • Apr. 8, 2026

You can still find Trefoil shortbreads and peanut butter Tagalongs.

From Los Angeles Times • Feb. 28, 2022

Seemingly in anticipation of the scheduled meeting between Mr. Blinken and Mr. Lavrov, the normally opaque Russian military recently took reporters on a tour of sites that included Trefoil Base, Russia’s northernmost military installation.

From New York Times • May 22, 2021

Balabeg A. Eminov is the commander of the anti-ship battery and other facilities on Franz Josef Land, called the Trefoil Base.

From New York Times • May 22, 2021

But the captain was a gentleman; he would have died sooner than harm a timber of the dear old Trefoil.

From The Cruise of the Snowbird A Story of Arctic Adventure by Stables, Gordon