What does cloverleaf mean?
A cloverleaf is a type of highway interchange designed so that two roads cross without any signal lights or stop signs. Viewed from above, its looping ramps resemble the leaves of a clover: traffic turning from one road to the other follows a curved 270-degree ramp that passes under or over the intersecting roadway. First built in the United States in the late 1920s, the design spread worldwide as an elegant solution to high-speed merging, though modern engineers often prefer modified versions because weaving traffic on the loops can cause congestion. The word can also, less commonly, refer to a single leaf of the clover plant, though this sense is now unusual outside botanical contexts. Familiar to nearly every driver, 'cloverleaf' carries no strong connotation beyond its practical, everyday association with road travel, and it is standard in both British and American English.
A grade-separated road junction with loop ramps resembling a four-leaf clover, allowing traffic to change roads without stopping.
"Exit the motorway at the cloverleaf and follow signs for the airport."
Almost always used in the context of road engineering and traffic.
A leaf of the clover plant.
"She pressed a cloverleaf between the pages of her book."
Less common than the road sense; usually written 'clover leaf' in this meaning.
Regular plural; the f does not change to v before -es.
"The region's oldest cloverleaves are being redesigned to handle heavier traffic."
The first cloverleaf interchange opened in New Jersey in 1929 — and engineers have been arguing about its safety ever since.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cloverleaf
The word combines 'clover', from Old English clāfre, with 'leaf', from Old English lēaf, both Germanic roots. Its use for a road interchange arose in early 20th-century America, when the layout's resemblance to the plant's leaves suggested the name; the first such interchange was built in Woodbridge, New Jersey, in 1929. The botanical compound is older, simply joining the names of the plant and its leaf.
How cloverleaf is actually used
In modern usage 'cloverleaf' almost always refers to the road interchange; the botanical sense is rare and usually appears as simply 'clover leaf'. The word is standard in both British and American English, though British speakers more often say 'interchange' or 'flyover'.
Easily confused with cloverleaf
Clover is the three- or four-leaved plant itself, while cloverleaf most often refers to a highway interchange shaped like that plant.