rude slang for Muslims. You shouldn't say it because it is offensive to most people.
Assholes will often discriminate against "pakis" because they accuse them of rape, theft, murder, etc... However, people that are racist to Muslims (or anyone for that matter) are dumbshits who think they are being sophisticated and important by calling their fellow humans "primitives" and "brown pieces of shit".
Good guy: "hey dude we got the same score on this math test"
"George": "oh cool"
Asshole: "dude omg thats imposserable"
Good guy: "shut the fuck up asshole"
(Good guy and "George" high five )
Today I went to the grocery store to get some food and some douchebag called this other guy a "Paki". I kicked the douchebag in the balls. Then I continued to mind my own business, and i bought some 2% milk, some cookies, and a bag of chips.