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Glite Dictionary
rocker arm

rocker arm

6.9
A lever that moves on a center point to open or close an engine valve
  • noun
  • /ˈrɑːkər ɑrm/
  • Specialized
translation icon : brazo oscilante
  • After replacing the worn-out rocker arms, the engine's performance improved significantly.
  • rods and rocker arms

And we got new rocker arms and, you know, you know, Jamie, he's.

Examples

  • And we got new rocker arms and, you know, you know, Jamie, he's.

    Gas Monkey Garage

  • America, if you need starters, spark plugs, ball joints gaskets, cam shafts, U-joints or rocker arms anything that can be screwed or glued to that car or truck of yours come see old Ray.

    Tommy Boy (1995)

  • The mechanic explained how the rocker arm functions to open the engine's valves during operation.

  • The technician demonstrated how to properly adjust the rocker arm clearance for optimal valve timing.

Synonyms

valve rocker
vsrocker arm
  • Specialized
7.6

A lever in an engine that moves the valve to open and close

is described as operating a valve to open or close it in engines

Surface Forms

rocker arm singular
rocker arms plural

Morphology

rocker + arm

The compound is partly compositional: 'rocker' (one that rocks/pivots) combined with 'arm' (a lever) transparently suggests a pivoting lever. However, the precise technical function in an internal combustion engine (opening and closing valves) is specialized and may not be fully predictable to a B1 learner who merely knows the constituent words, so the term is only partially transparent.

Etymology

Rocker arm comes from the image of a short engine 'arm' that rocks like a seesaw to push a valve. The word rocker shows the back-and-forth motion and arm shows it acts like a lever, so the name describes the engine part that opens and closes valves.