Conservator was a Cardassian occupation, vaguely similar to a public defender. Unlike their Human counterpart, Conservators were not supposed to win a case. Rather, the role was to prepare the accused for a moving confession of guilt on the floor of the court.
Kovat was one of most popular and widely known conservators in the Cardassian Union in the 2360s and 70s. In 2370, he actually won a case, 'representing' Miles O'Brien in a charge of supplying arms to the Maquis. Unfortunately he was only a few days to retirement. (DS9: "Tribunal")