We found 15 dictionaries that define the word brightening:

General (12 matching dictionaries)

1. brightening: Merriam-Webster
2. brightening: Collins English Dictionary
3. brightening: Vocabulary.com
4. Brightening, brightening: Wordnik
5. brightening: Cambridge Advanced Learner's Dictionary
6. brightening: Wiktionary
7. Brightening, brightening: Dictionary.com
8. brightening: Cambridge Essential American English Dictionary
9. Brightening: Online Plain Text English Dictionary
10. brightening: FreeDictionary.org
11. brightening: TheFreeDictionary.com
12. Brightening: AllWords.com Multi-Lingual Dictionary

Business (1 matching dictionary)

13. brightening: Legal dictionary

Slang (1 matching dictionary)

14. brightening: Green’s Dictionary of Slang

Tech (1 matching dictionary)

15. AUTOMOTIVE TERMS (No longer online)

(Note: See brighten as well.)

Definitions from Wiktionary (brightening) ▸ noun:  An instance of becoming brighter. Similar: lighten, light up, lighten up, clear up, clear, bright, brightsomeness, shining, illuminant, illumining, more... Opposite: darkening, dimming, obscuring Phrases: brightening agents, limb brightening, brightening agent, eye brightening, Anglo-Frisian brightening, more... Adjectives: sudden, general, little, gradual, slight, optical, momentary, rapid, daily, initial, faint Colors:     yellow,     lemon,     lime,     sky blue,     turquoise, more... ▸ Words similar to brightening ▸ Usage examples for brightening ▸ Idioms related to brightening ▸ Wikipedia articles (New!) ▸ Popular adjectives describing brightening ▸ Words that often appear near brightening ▸ Rhymes of brightening ▸ Invented words related to brightening