What is the most accurate translation of the word 'dukkha'?

This question is a sequel to my previous question about First Noble Truth. It seems that there is discord about the exact rendering of the word 'dukkha'. Sorry if I sound like a pedantic dou*h. I am just trying to understand it clearly. So the answer I received in this link and this link translates it as 'stress'. (I personally think it's wrong, but I am not any authority or scholar). The Wikipedia page for dukkha gives the following translations: "suffering", "unhappiness", "pain", "unsatisfactoriness" or "stress". So what's the exact meaning? I am asking because the exact rendering changes the meaning and its effectiveness as teaching a lot.