D defs.my
Entry 1 sense Webster, 1913

Lock washer

/läk wäsh'-ẽr/ · Lock· wash·er · IPA
01 n. A washer that is not completely smooth or flat, designed to prevent a nut from loosening, placed under the nut on a screw or bolt.
  1. 1.
    A washer that is not completely smooth or flat, designed to prevent a nut from loosening, placed under the nut on a screw or bolt.