As we walked along Granville looking for Ouisi (with my "infallible" sense of direction, I had turned right - south instead of north from our parking spot on 12th), we were speculating about the origin of the name. Since it could be deconstructed as oui and si, we decided that it must mean "yes, yes." Great name for a restaurant, we thought. But after we found the place and were seated, Catherine, our smiling server, said it came from the middle part of Louisiana. We should have guessed since it serves Cajun and Creole food.