What is the meaning of riddle?

noun

• A difficult problem.
  • synonyms: conundrum, enigma, brain-teaser
• A coarse sieve (as for gravel. )

verb

• Pierce with many holes.
  • usage: "The bullets riddled his body"
• Set a difficult problem or riddle.
  • usage: "riddle me a riddle"
• Separate with a riddle, as grain from chaff.
  • synonyms: screen
• Spread or diffuse through.
  • usage: "An atmosphere of distrust has permeated this administration"; "music penetrated the entire building"; "His campaign was riddled with accusations and personal attacks"
  • synonyms: permeate, pervade, penetrate, interpenetrate, diffuse, imbue
• Speak in riddles.
• Explain a riddle. .