brightens; brightened; brightening
1
: to add more light to (something)
He brightened the picture on the television.
2
a
: to make (something) more colorful or cheerful
Flowers can brighten any room.
The good news brightened her mood.
—often + upShe always brightens up a party.
You really brightened up my day.
b
: to become brighter or more cheerful
The sky brightened after the storm.
Her mood brightened.
Her eyes brightened.
Business prospects brightened last month.
Her face brightened in relief when she heard that he was not hurt.
Cite this Entry
“Brighten.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/brighten. Accessed 15 Jun. 2026.
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