D defs.my
Entry 1 sense Webster, 1913

Polarizer

/pōl'-ẽr-īzˌ-ẽr/ · Po·lar·i·zer · IPA /pˈoʊlərˌaɪzər/
01 n. That which polarizes; especially, the part of a polariscope which receives and polarizes the light. It is usually a reflecting plate, or a …
  1. 1.
    That which polarizes; especially, the part of a polariscope which receives and polarizes the light. It is usually a reflecting plate, or a plate of some crystal, as tourmaline, or a doubly refracting crystal.(Physics)