What is the meaning of dingy?

adjective

• Thickly covered with ingrained dirt or soot.
  • usage: "a miner's begrimed face"; "dingy linen"; "grimy hands"; "grubby little fingers"; "a grungy kitchen"
  • synonyms: begrimed, grimy, grubby, grungy, raunchy
• Of color. ( discolored by impurities; not bright and clear)
  • usage: "dirty" is often used in combination; "a dirty (or dingy) white"; "the muddied grey of the sea"; "muddy colors"; "dirty-green walls"; "dirty-blonde hair"
  • synonyms: dirty, muddied, muddy
• Causing dejection.
  • usage: "a blue day"; "the dark days of the war"; "a week of rainy depressing weather"; "a disconsolate winter landscape"; "the first dismal dispiriting days of November"; "a dark gloomy day"; "grim rainy weather"
  • synonyms: blue, dark, disconsolate, dismal, gloomy, grim, sorry, drab, drear, dreary