If something is out of place in French it is hors du commun. If it is out of your price range it is hors de prix. Être hors de danger is to be out of danger. An outboard motor is a moteur hors-bord. And fugitives live outside the law or hors-la-loi.
To say you are at work in French you will most likely say je suis au travail but you could also say je suis à l’oeuvre. If you implement something (ie. put it to work) you mettre en oeuvre.
Put together the pieces and an hors d’oeuvre is something that is outside the work, the main course being the work.