What does fusee mean?
A fusee is a specially shaped pulley — a shallow cone cut with a deep spiral groove — used in mechanical clocks and watches to solve an old problem of springs. A coiled mainspring delivers more force when fully wound than when nearly spent, so early makers paired it with a chain running between the barrel and the fusee's tapered groove; as the spring unwinds, the chain shifts onto a wider radius, evening out the torque. Invented around the fifteenth century, the fusee remained the hallmark of accurate portable timekeeping until the modern going barrel displaced it in the nineteenth century, and it survives today chiefly in antique and high-grade collectible pieces. The name also once referred to a slow-burning match used to carry fire, particularly in lighting cannons or pipes. Derived from the French fusée, meaning spindle or rocket, the word belongs to a family of terms built on the idea of a spindle-shaped object, including fusiform in biology. For collectors, the phrase 'fusee and chain' instantly evokes fine pre-industrial craftsmanship.
nounA conical, spirally-grooved pulley used in mechanical clocks and watches to equalize the pull of the mainspring; more broadly, any similarly shaped cone or spindle-like device.
- A conical, spirally-grooved pulley (with its chain) used in clocks and watches to equalize the varying force of the mainspring as it unwinds
- Historically, a wooden match or cord soaked in combustible material, used for lighting gunpowder or pipes
"The antique marine chronometer's fusee and chain were still perfectly intact."
"The antique marine chronometer's fusee and chain were still perfectly intact."
"He lit his pipe from the smouldering tip of a fusee."
The plural follows standard English formation; note that the similar-looking Italian musical term 'fusée' (a rapid run) is unrelated in meaning.
"The workshop drawer held spare fusees of every size."
Before the modern mainspring could keep steady time, watchmakers wound its power through a tiny spiral cone called a fusee — a 15th-century invention so clever it survived in precision timepieces for over four hundred years.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of fusee
The word derives from the French fusée, itself rooted in Latin fusus, meaning a spindle — the tapered wooden tool used in spinning thread. This origin explains both senses: the conical spindle shape of the horological pulley, and the tapering stick of the burning match. The term entered English in the sixteenth or seventeenth century as watchmaking technology spread across Europe. Related words from the same Latin root include fusiform, describing spindle-shaped biological structures, and, via later French developments, fuselage and fusilier.
How fusee is actually used
The word carries strong technical associations with horology and antique clockwork; among collectors and restorers, 'fusee movement' signals a high-grade traditional mechanism. The older sense of a burning match survives only in historical contexts.
Easily confused with fusee
A fusil is a lightweight firearm, whereas the fusee is a grooved conical pulley in clockwork — both trace back to French 'fus-' forms but denote entirely different things.
A fuze (or fuse) is a device for detonating an explosive or completing an electrical circuit, while a fusee is the horological pulley that regulates a spring's power.