trefoil

noun

1
a
: clover sense 1
broadly : any of several leguminous herbs (such as bird's-foot trefoil) with leaves that have or appear to have three leaflets
b
: a trifoliolate leaf
2
: an ornament or symbol in the form of a stylized trifoliolate leaf

Illustration of trefoil

Illustration of trefoil
  • trefoil 2

Examples of trefoil in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The British royal wore a petite diamond ribbon brooch, which features a ribbon design in a trefoil shape. Julia Teti, WWD, 16 July 2024 How long does a rope have to be in order to form a trefoil knot? Kevin Hartnett, Quanta Magazine, 5 Jan. 2024 The simplest torus knot — indeed, the simplest nontrivial knot, period — is called a trefoil. Kevin Hartnett, Quanta Magazine, 5 Jan. 2024 The mathematics of knot theory says that a simple loop and a trefoil are fundamentally different knots. George Hart, Scientific American, 22 Jan. 2013 See all Example Sentences for trefoil 

Word History

Etymology

Middle English, from Anglo-French, from Latin trifolium, from tri- + folium leaf — more at blade

First Known Use

15th century, in the meaning defined at sense 1a

Time Traveler
The first known use of trefoil was in the 15th century

Dictionary Entries Near trefoil

Cite this Entry

“Trefoil.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/trefoil. Accessed 28 Nov. 2024.

Kids Definition

trefoil

noun
1
: any of several herbs (as a clover) of the legume family with leaves that have or appear to have three leaflets
2
: an ornament or symbol shaped like a leaf with three parts

More from Merriam-Webster on trefoil

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!