"long time no see"的定义和意义

What is the origin of the idiom "long time no see" and when to use it?

The exact origin of the idiom "long time no see" is not precisely documented, it is believed to have originated from a direct translation of a similar phrase in Native American Pidgin English in the late 19th century. It is an informal and friendly greeting used to express that it has been a while since the speaker last saw the other person.