1930s; earliest use found in Brevities (New York). From pee, the name of the letter P + em, the name of the letter M, after p.m. n.1.
英语词典包含243303条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。