Cruk

Cruk was a 26th century English language swear word used within the Terran Federation, and perhaps more broadly amongst humans in general. It was a favourite word of Bernice Summerfield, but she was hardly its only employer. The staff of the Pandora Spindle, for instance, were also quite fond of it. (PROSE: Love and War, Human Nature, AUDIO: The Final Amendment, COMIC: Pureblood)

Behind the scenes
Like Battlestar Galactica's frak, the word was a "space age" equivalent of fuck, which could be used in exactly the same situations as the modern-day swear word. It was invented by Paul Cornell, and has been associated with Benny since her first story, Love and War.