1. [noun] A secondary scale with finer graduations than the primary scale of a measuring device; the vernier measures between graduations of the larger scale.
2. [noun] A secondary control input with finer control than the primary, or coarse, input; for example the vernier frequency tuning knob on a radio.
3. [noun] (physics) A secondary system of force application for the attitude control of a spacecraft; for example a vernier thruster.
4. [noun] French mathematician who described the vernier scale (1580-1637).
5. [noun] A small movable scale that slides along a main scale; the small scale is calibrated to indicate fractional divisions of the main scale.
