noun / adjective
vernier
VUR-nee-er/vˈɝniɝ/
An auxiliary scale or mechanism for precise measurement or fine adjustment.
The vernier helps her read the measurement to a fraction of a millimeter.

Etymology
The scale takes its name from French mathematician Pierre Vernier, who described it. Its name commemorates its inventor rather than describing how the sliding scale measures.
In context
I will move the vernier scale so this time I have something a slightly different these three lines coincide with three lines in the main scale
More examples
- She uses a vernier caliper to check the tube's diameter.
- The vernier control lets us make tiny adjustments to the instrument.
- Both verniers have markings that align with their main scales.
Forms
vernier · verniers
Similar words
- micrometer
- Typically uses a calibrated screw for precise measurement or adjustment.
- scale
- Shows measurement divisions but need not provide especially fine readings.