枯木逢春

kūmùféngchūn
  1. lit. the spring comes upon a withered tree (idiom)
  2. fig. to get a new lease on life
  3. to be revived
  4. (of a difficult situation) to suddenly improve

CEDICT

to get a new lease of life in a desperate situation

Wiktionary

比喻雖處於絕境卻重獲生機，或劣境忽然轉好。《喻世明言．卷九．裴晉公義還原配》：「兩口兒回到家鄉，見了岳丈黃太學，好似枯木逢春，斷弦再續，歡喜無限。」也作「枯樹生華」。

重編國語辭典

雖處於絕境卻重獲生機，或劣境忽然轉好

維基詞典

Entry Composition

1 枯木 kūmù dead tree
2 逢 féng
  1. to meet by chance
  2. to come across
  3. (of a calendar event) to come along
  4. (of an event) to fall on (a particular day)
  5. to fawn upon
=3 春 chūn old variant of 春 chūn
=3 春 chūn
  1. spring (season)
  2. gay
  3. joyful
  4. youthful
  5. love
  6. lust
  7. life