NU!
Once upon a time, many years ago, when our Yiddish-speaking grandparents and great-grandparents were alive, everyone knew what "Nu" meant.
It went without saying. They were only newcomers to the "Golden Land" then. Life was a struggle and they didn't have much patience. Everything was measured carefully, even words. So just the mere sound of a demanding, gnawing "Nu," kept children in line. It sent many of us scurrying to shul or Hebrew School, or just plain kept us out of trouble.
But those days are gone. It is rather difficult to explain even to an educated, sophisticated and literate contemporary person the full impact and many nuances of this short little word. Furthermore, even if they understood, today's modern people would refuse to listen. They'd complain it gives them a Nurosis. Vey iz mir!
The only place in today's world where one can still hear something somewhat similar to the primal nu is in Israel, where it is reported that the cows still keep faithfully repeating "Noo, Noo" to this very day.
Unfortunately, the English language has no phrase, paragraph or even page that can do justice to the good old-fashioned "Nu." All Webster's dictionary could think of is the gnu, a wild animal that isn't even kosher. All the American Public ever heard about is Sununu, who isn't even Jewish. Nu, need I say more?
So what else is Nu? We'll soon be entering the month of Adar I. Though Purim isn't celebrated until Adar II some people are already tuning up their groggers. And with a whole extra month to practice noise-making at the sound of Haman's name, how will we continue the Megilla reading when those tuned-up groggers, stamping feet and clapping hands refuse to stop? Nu? What do you do?
You use the un-word. All you need is a few strong Nus, and the shul decorum is restored without saying a word! In fact, the puny little "Nu" can produce better results than those long formal lawyers letters with all their newfangled multi-syllable words.
On the other hand, Nu is not No, and No is not Nu. While its tone shows a hint of disappointment, it also expresses the confidence that we know better. It only insinuates, without spelling it all out. For nudging too much is a nu-nu.
Nu! Enough of this nonsense! Let's stop this nuisance and get a little more serious. Let' think back to the Nu age. When our parents or relatives said: "Nu?" they meant business. They expected more of us. "Nu, so when will you settle down already?" Or, "Nu, can you ever become a Mentch?!" Indeed, no nus is not good news! Nu?!