1. A completely and totally unnecessary expletive with no real meaning.
2. The act of engaging in sexual congress with a man/woman named Sampson.
Let's get the sampsonfuck outta here!
Mary-Beth: I fucked John last night.
Jacqueline: Isn't his last name Sampson?
Jacqueline: Wow! Was that your first Sampsonfuck?
Jacqueline: You must be very proud.