[hào shǒu qióng jīng]   

皓    首    穷    经    皓：白；首：头发；穷经：专心研究经书和古籍。一直到年老头白之时还在深入钻研经书和古籍。 褒义>

成语“穷经皓首”，指一直到年老头白之时还在深入钻研经书和古籍。出自韩偓《赠易卜崔江处士》：“白首穷经通秘义。”

A hoary head does research in the classics -- an aged person still learns

皓月千里    皓齿娥眉    皓齿朱唇    皓齿青蛾    皓首苍颜