半路出家 bànlù-chūjiā

(1) [adopt a profession (trade) rather late in one's life;become a monk or nun late in life]∶年纪大了才脱离家庭去当和尚或尼姑

(2) [start midway]∶比喻原先并不是从事这一工作的,后来才改行从事这一工作