What is the meaning of dimmer?

noun

• A rheostat that varies the current through an electric light in order to control the level of illumination.

adjective

• Lacking in light; not bright or harsh.
  • usage: "a dim light beside the bed"; "subdued lights and soft music"
  • synonyms: dim, subdued
• Lacking clarity or distinctness.
  • usage: "a dim figure in the distance"; "only a faint recollection"; "shadowy figures in the gloom"; "saw a vague outline of a building through the fog"; "a few wispy memories of childhood"
  • synonyms: dim, faint, shadowy, vague, wispy
• Made dim or less bright.
  • usage: "the dimmed houselights brought a hush of anticipation"; "dimmed headlights"; "we like dimmed lights when we have dinner"
  • synonyms: dimmed, dim
• Offering little or no hope.
  • usage: "the future looked black"; "prospects were bleak"; "Life in the Aran Islands has always been bleak and difficult- J. M. Synge; "took a dim view of things"
  • synonyms: black, bleak, dim
• Slow to learn or understand; lacking intellectual acuity.
  • usage: "so dense he never understands anything I say to him"; "never met anyone quite so dim"; "although dull at classical learning, at mathematics he was uncommonly quick- Thackeray; "dumb officials make some really dumb decisions"; "he was either normally stupid or being deliberately obtuse"; "worked with the slow students"
  • synonyms: dense, dim, dull, dumb, obtuse, slow