Correct, though a wanker is somebody who self stimulates said knob. 
  
In the context used, dick, prick, rooster, douchebag, wanker, knobend, peckerhead, tosser and dickhead would all appropriately fit. 
  
 
I think Nanker covered the definition fairly well....I've elaborated above. 
  
Lol....yeah, everybody in the commonwealth thinks the monarchy is great.  None of us want our countries to become republics.