When pressed if he knew what it meant, he said (correctly, although I don't know if he knew he was correct), "I don't know." Whether or not he knew it, that was the correct meaning of the phrase. I just smiled and didn't press the issue.
It means "I don't know what" or an undefinable not necessarily absent something; in a phrase that is more familiar, it's like an "x-factor." To use a trite example, "that person has a certain je ne sais quoi." (Sounds like something the writers of "pit and pab"
It just struck me that we use so many words and cliches that we don't really know the meaning to but by oral tradition, we've become so used to them. Law students are no exception; they love to toss around huge and profound sounding terms that don't necessarily mean huge and profound things. Many times really, simple is just better.
In the meantime, could you, as a prefatory matter, indulge me by passing the certiorari to alleviate the conundrum that I am in?