TheBoost said:

Lucas has robbed the term of all meaning, in fact he's robbed it of even a reason to exist. If the MacGuffin is the vital central part of the film, of great importance to the characters and the audience, then there's no need to have a term for it.

I entirely agree. This kind of abuse of language infuriates me. It is slowly robbing the English language of its precision and elegance. I seem to remember C.S. Lewis making a similar case in respect of the word gentleman.

This is all the fault of descriptivist modern grammarians with no respect for the traditions of the English language who are too eager to invoke the all-excusing "languages change over time" argument to accommodate all manner of sloppy uneducated speech. The day will soon come when have to use whole clauses and phrases to explain simple concepts for which we once had useful efficient words.