^ I disagree. That definition says, first, that the short version is the executive producer that serves as head writer. Neither Berman nor Roddenberry were ever the head writer of TNG.
The longer definition says "the person who gives the show its tone and direction." Using THAT definition, I can see that applying to Roddenberry in the first season and to Roddenberry and Maurice Hurley together in the second season. But never Rick Berman. The person setting the tone and direction, creatively, of TNG from the third season onward was most definitely Michael Piller. I think he would clearly be called the showrunner. Perhaps around season six or seven, when he stepped back a bit, you could say Jeri Taylor, but even then, Piller was still ultimately in charge of the writing room.
Although Rick Berman was the final authority, and did have input into the creative decisions, he certainly did not have the level of direct supervision over the writing room as Piller did, and Piller clearly set the tone and direction of the show.