godan verb (-su)
spend one's days and nights doing
Used with a verb in the 連用形 (continuative form) to describe spending all one's time engaged in that activity. Often carries a nuance of being absorbed in something, sometimes to the point of neglecting other things.
彼は研究に明し暮らしている。
He spends all his days and nights on research.
小説を読み明し暮らした夏休
It was a summer vacation spent reading novels day and night.