Why are the Buddhist monks termed "Heshang" in China? What does it mean?
出家男子为什么称为和尚？和尚是什么意思？

The word "Heshang" was derived from the Sanskrit Upādhyāya,(P. Upajjhāya), meaning teacher or mentor. The word was pronounced as Pwājjhaw or Khosha in the regions to the West of China. From there to the Han-inhabited area it was changed into Heshang. Originally it was an honorable title only for those who were capable to be masters, and not to anybody else. This title at first had not been confined to Buddhist monks but might equally be applied to qualified Buddhist nuns. Later on, this word came to be used to address any male who is leading a monastic life. It is not in conformity to the original meaning.
“和尚”原来是从梵文Upādhyāya（P. Upajjhāya）这个字出来的，这个字到了西域被读成“乌阇”，到了汉地又读成“和尚”，它的意思就是“师”。和尚本是一个尊称，要有一定资格堪为人师的才能够称和尚，不是任何人都能称的。这个称呼并不限于男子，出家女众有资格的也可以称和尚。但是后来习俗上这个字被用为对一般出家人的称呼，而且一般当作是男众专用的名词，这是和原来的字义不合的。