What is the meaning of illuminating?

verb

• Make lighter or brighter.
  • usage: "This lamp lightens the room a bit"
  • synonyms: light, illume, illumine, light up, illuminate
• Make free from confusion or ambiguity; make clear.
  • usage: "Could you clarify these remarks"; "Clear up the question of who is at fault"
  • synonyms: clear, clear up, shed light on, crystallize, crystallise, crystalize, crystalise, straighten out, sort out, enlighten, illuminate, elucidate
• Add embellishments and paintings to (medieval manuscripts.
  • synonyms: illuminate

adjective

• Tending to increase knowledge or dissipate ignorance.
  • usage: "an enlightening glimpse of government in action"; "an illuminating lecture"
  • synonyms: enlightening, informative