What is a "Dit" name you ask.

Well, according to all the sources I have found;

• The Short Definition:
  "The word "dit" is the past participle of the French verb "dire" - to say. Literally, then, the dit name is the name that was "said" rather than than the actual family name. One could translate it as "alias" or A.K.A. It was a French way of distinguishing different Joseph Papineau's from one another. "

• The More Explanative Version (by Jann LaValley <glavalley@johnabbott.qc.ca>):
  Some of this is guesswork and some is known. If you think of the translation more as 'called' than said it might be more useful for you. I believe that some of it arose from the fact that in the days of early French Canada the settlers were encouraged to have large families and there were not a lot of options as to whom you could marry.  Within two or three generations the small communities would have, as in our family several people with the same name, cousins and second cousins.  The 'dit' names came about from people's efforts to differentiate one from another and they would use a physical feature, or the person's trade or even where they lived.  In addition to people called 'Lavallee dit pret a boire' (ready for a drink) there were other 'Legrain dit Lavallee' so I assume that this particular Legrain lived in a Valley.
  
  Some of the 'dit' names came about from the camaradie of the soldiers in the Carignan regiment and the nicknames they used for each other. In other situations the dit name refers to the given name of the father so you have in Sorel quite a number of people whose surname is Hus but also another group called Hus-Paul because they descended from Paul Hus rather than one of his brother's.  I have come to the conclusion that sometimes the first son of a family would take the dit name and others wouldn't.  I often think that I have finally figured it out and then the next time I go to do research something proves me wrong <g> 
  
  Another thing to consider is that the 'dit' names arose in much the way that English surnames arose in the 12th and 13th century.  Place names , occupations, physical features and the true patronymic like Robinson = Robin's son. It is not terrifically important to be able to pin down the reason why though,  I would just consider it one more helpful thing in trying to trace our ancestors.
  
  One more thing I would like to add to the above is that depending on the records and/or index you are looking in the transcribers may have used different conventions.  Some of them take note of the 'dit' names and some of them place everyone under the original name.  I even suspect that some of the clergy would add a 'dit' name where none had been given which could be very confusing if he had come from a different parish where the 'dit' name was quite different from the one used in the new parish and he just added one to the record on an assumption.  I think they often considered that they were 'superior' to the 'peasants' and knew better than they did.  If you have trouble locating someone use absolutely every clue you can to track them down.  I was looking in the Loiselle Index on Friday for someone I thought would be recorded as Delard.  By switching back and forth through the Male and Female indexes I eventually found them as 'Dillaire'.  Nothing to do with 'dit' names here but to illustrate using what you already have to get to what you want. Even if you know which 'dit' name it is supposed to be, if you don't find it carry on looking through any other known 'dit' name for that group. Most of the resource books and indexes have lists of all the known ones.
  
  

• According to the American French Genealogy Society (AFGS), there are 11 different dit names associated with the surname Papineau.

  They are:  Bourdignon, DeMontigny, Deslauriers, Forville, Montigni, Montigny, Montigny (De), Papenaw, Perillard, Testard, Deslauriers. Although I have found 4 others (Tetard, Fortville, Popenoe, and Poppino) and have told AFGS about them.