A synonym for the word 'cunt'.
Referring to the esteemed Formula 1 driver Alain Prost whose attitude throughout his career and especially towards the great Ayrton Senna was that of a complete cunt.
Probably didn't help that he was French either.
Person 1: Where's the milk?
Person 2: I finished the last of it.
Person 1: You're such a Prost.