Here is an article I put on the "Canada" page years ago, cut-&-paste: >> Dit-names are an unusual feature of French culture. It was common for families to have two "last" names. One was considered their "nom de famille", the other was the "surnom". There is really no English equivalent to that tradition, but if you translate "dit" as "also known as" or "alias" or "called", you'll be close.
Dit(pronounced "dee")-names were chosen for any number of reasons: a) personal nicknames: - Miville dit le Suisse, Bernier dit Jean de Paris, Pelletier dit le Gobloteur; these were often unique, and dit not survive more than one other generation b) military "noms de guerre": - Charles dit Lajeunesse, Soucy dit Lavigne; when someone joined the army (as in the French Foreign Legion today) they were hazed in and given a new name. Several soldiers stayed in Canada in the 1660s, and these names have become very common throughout Canada and the USA, although generally they are not found in France. c) place of origin: - Gareman dit le Picard, Mignot dit Labrie. A number of the regions and cities of France are reflected in such names, e.g. Potvin, Normand, LaRochelle. d) property or seigneury: - DesChamps, Dutilly e) physical features: - LeBlanc, Rousseau f) patron saint: - St-Pierre g) minor nobility: - Chatillon, ...
After the British took over in Canada, they actively discouraged the use of dit-names. So in the 1800s, families would choose one or the other. It would even result in brothers having different last names. So when researchers like you are stuck in that period, it is important to keep open the possibility that the earlier generation was known by the other name. >>
In your case, I suspect that "Bonvivant" was given to a soldier, as his nom-de-guerre.You might enjoy reading message # 153 on the "Dufour" forum.