Definition of trefoil
1a : clover 1; broadly : any of several leguminous herbs (such as bird's-foot trefoil) with leaves that have or appear to have three leafletsb : a trifoliolate leaf
2 : an ornament or symbol in the form of a stylized trifoliolate leaf
Recent Examples of trefoil from the Web
The latest inexplicable fad has young teens building collections of the palm-sized trefoils.
A four-leaf clover, on the other hand, is a mutation of the trefoil plant that superstitious people believe carries good luck.
By the 1930s, as enrollment soared to more than 200,000 members (up from a mere 18 in 1912), the organization regularly issued tools such as pocket knives, first-aid kits, match safes, and canteens emblazoned with their trefoil logo.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'trefoil.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
TREFOIL Defined for English Language Learners
Definition of trefoil for English Language Learners
: a plant (such as a clover) that has three leaves on each stem
: a decorative object or design that is shaped like a leaf with three parts
TREFOIL Defined for Kids
Definition of trefoil for Students
1 : a clover or related plant having leaves with three leaflets
2 : a fancy design with three leaflike parts
Seen and Heard
What made you want to look up trefoil? Please tell us where you read or heard it (including the quote, if possible).