D defs.my
Entry 1 sense Webster, 1913

Interferometer

/ĭnˌ-tẽrf-ẽr-äm'-ət-ẽr/ · In·ter·fe·rom·e·ter · IPA /ˌɪntərfərˈɑmətər/
01 n. An instrument for measuring small movements, distances, or displacements by means of the interference of two beams of light; -- formerly al…
  1. 1.
    An instrument for measuring small movements, distances, or displacements by means of the interference of two beams of light; -- formerly also called also refractometer, but that word now has a different meaning.(Physics) Also: refractometer