it is used for cursing like "pinchi rasista" would be something like "fucking racist"
it comes from the word pinche, an adjective. Thats how someone that has the lower position within a company is called. the word pinche can be used for cursing also.
Kevin: dont you ever dare to remind me that pinchi slut again!!
2- What the verga do you dink youre doing with that pinche cucumber?!?!!!!!?