lever

[lev-er, lee-ver] /ˈlɛv ər, ˈli vər/
noun
1.
Mechanics. a rigid bar that pivots about one point and that is used to move an object at a second point by a force applied at a third.
Compare machine (def 4b).
2.
a means or agency of persuading or of achieving an end:
Saying that the chairman of the board likes the plan is just a lever to get us to support it.
3.
Horology. the pallet of an escapement.
verb (used with object), verb (used without object)
4.
to move with or apply a lever:
to lever a rock; to lever mightily and to no avail.
Origin
1250-1300; Middle English levere, levour for *lever < Anglo-French; Old French levier, equivalent to lev(er) to lift (< Latin levāre to lighten, lift, verbal derivative of levis light) + -ier -ier2
Related forms
relever, verb (used with object)

Lever

[lee-ver] /ˈli vər/
noun
1.
Charles James ("Cornelius O'Dowd") 1806–72, Irish novelist and essayist.
Examples from the web for lever
  • All these transmissions are selectable using the control behind the gear lever.
  • This allows the oars to act as a lever of force, rather than a paddle.
  • The scoops in the hood could be opened and closed via a lever under the dashboard.
  • The mechanism is worked by moving a rectangular lever forward and backward.
British Dictionary definitions for lever

lever

/ˈliːvə/
noun
1.
a rigid bar pivoted about a fulcrum, used to transfer a force to a load and usually to provide a mechanical advantage
2.
any of a number of mechanical devices employing this principle
3.
a means of exerting pressure in order to accomplish something; strategic aid
verb
4.
to prise or move (an object) with a lever
Derived Forms
lever-like, adjective
Word Origin
C13: from Old French leveour, from lever to raise, from Latin levāre, from levis light
Word Origin and History for lever
n.

c.1300, from Old French levier (Modern French leveur) "a lifter, a lever," agent noun from lever "to raise," from Latin levare "to raise," from levis "light" in weight, from PIE root *legwh- "light, having little weight; easy, agile, nimble" (cf. Sanskrit laghuh "quick, small;" Greek elakhys "small," elaphros "light;" Old Church Slavonic liguku, Lithuanian lengvas "light;" Old Irish laigiu "smaller, worse;" Gothic leihts, Old English leoht "light" (adj.)). As a verb, 1856, from the noun.

lever in Science
lever
  (lěv'ər)   
A simple machine consisting of a bar that pivots on a fixed support, or fulcrum, and is used to transmit torque. A force applied by pushing down on one end of the lever results in a force pushing up at the other end. If the fulcrum is not positioned in the middle of the lever, then the force applied to one end will not yield the same force on the other, since the torque must be the same on either side of the fulcrum. Levers, like gears, can thus be used to increase the force available from a mechanical power source. See more at fulcrum, See also mechanical advantage.