To brighten is to make something lighter, the way you brighten your back yard with glowing patio lights or brighten up your gloomy bedroom by painting the walls yellow.

When the sun comes out after several rainy days, it brightens your house and the walk to school, but it can also brighten your mood. This verb is perfect for both ways of making things light and cheerful — adding something that emits light or lending a happy or hopeful mood to a situation. Your best friend may be so funny and positive that they brighten a room just by walking in.

Definitions of brighten
  1. verb
    make lighter or brighter
    “The paint will brighten the room”
    synonyms: lighten, lighten up
    see moresee less
    make dark or darker
    type of:
    alter, change, modify
    cause to change; make different; cause a transformation
  2. verb
    become clear
    synonyms: clear, clear up, light up
    see moresee less
    cloud, overcast
    make overcast or cloudy
Word Family

Test prep from the experts

Boost your test score with programs developed by’s experts.

  • Proven methods: Learn faster, remember longer with our scientific approach.
  • Personalized plan: We customize your experience to maximize your learning.
  • Strategic studying: Focus on the words that are most crucial for success.


  • Number of words: 500+
  • Duration: 8 weeks or less
  • Time: 1 hour / week


  • Number of words: 500+
  • Duration: 10 weeks or less
  • Time: 1 hour / week


  • Number of words: 700+
  • Duration: 10 weeks
  • Time: 1 hour / week