Otherf–

A phrase starting with "Otherf" was used by the Time Lord Gandarotethetledrax. He used it in reference to the Eighth Doctor in saying, "Let’s just kill the Otherf–" before being cut off. (PROSE: The Shadows of Avalon)

Behind the scenes
The word could be interpereted as "Otherf*cker", a variation of "Motherf*cker" that references the Other.