Onychoatrophy is a faulty underdevelopment of the nail that may be congenital or acquired, in which the nail is thinned and smaller.James, William; Berger, Timothy; Elston, Dirk (2005).
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。