brighten
/ˈbraɪtn; `braɪtn/ v[I, Ip, Tn, Tn.p]
~ (sth) (up) (cause sth/sb to) become brighter, more cheerful or more hopeful （使某人[某事物]）焕发光彩, 更愉快, 更有希望
The sky/weather is brightening. 天空[天气]转晴.
He brightened (up) when he heard the good news. 他听到这个好消息时喜形於色.
Flowers brighten (up) a room. 房间里有了花显得满室生辉.