Q: Excuse me, professor. Could you tell me the meaning of "student
     body"? This is my first time to know this new word. So I'm extremely
     curious about its different meaning      from what I know of this word..
     Thanks a million.
A: “Body” has several meanings
      First, we know it means physical structures of human beings and animals. Sometimes, the meaning of body excludes the head and limbs. Body in this sense is related to anatomy which is the study of our physical structure in order to treat diseases or examine corpse of the dead for the police to resolve cases of murder.  Sometimes, body refers to a substantial section of a writing like content of a letter which you may hear people say “letter body” (內容).
      Speaking of “student body”, you can’t interpret it as our eyes, noses, lips or other parts of our physical appearance when someone is talking about student activities or clubs. (If you do so, it can make you sound absurd and thus embarrass you.)  Since “body” comes after “student”,  it indicates activities student do on campus. In order to organize so many things done in a school setting, students need a union to help them. This union is formed by a group of students who are elected from all student populations. It means that those students represent the departments and colleges they are from. In Chinese, we call it 學生代表聯合會 or 代聯會. The union represents students to speak in university board and faculty if students have petitions for their benefits. Within the university regulations, student union plans and organizes activities to highlight students’ campus life.  Student body is a nick name for student union, or student government. All these terms refer to the same thing. Sometimes you may also hear people say “student governor”. They are the representatives firstly elected by the departments then to the final election in the colleges. So student governors represent colleges and departments for student welfare.
      You are asking me to write a PhD dissertation. Besides, I have very limited knowledge on Latin. My expertise is on English teaching. I am afraid your question has to be referred to professors who study both Latin and Chinese. However, I shall find someone who can better reply your question.