noun: any annoying/inconvenient/unwanted/unkind situation/person that can be considered both a rightbastard and a complete fuck.
1) Max goes out at 6:30am to leave for work and discovers the front tyre on his bike is completely flat. Max looks angrily at the tyre and proclaims "oh you bastard-fuck!".
2) Miriam goes to the fridge for her half of that chocolate cake she's been looking forward to all day, only to discover that her brother Danny has eaten it. "That was for me Danny you bastard-fuck" she then wails.
One who either plays practical jokes on another, or who is just an annoying bitch. The word is typically used to berate a personal friend for doing something to you. I.E., if a friend shits on your chest, he or she is, by definition, a bastardcock. He or she is also fucked up. Really fucked up.