白首空悲执笔几许
[bái shŏu kōng bēi zhí bĭ jĭ xŭ]
The phrase '白首空悲执笔几许' translates to 'writing sorrowful regrets as white-haired falls upon.' It conveys someone who is lamenting the passing of time with only writing to remember youthful ardors or dreams that didn't come true, reflecting profound feelings like remorse or sadness over lost opportunities or youth in one's old age.