A player on the Chicago Cubs, if reading this in the future, a former player for the Chicago Cubs. However his baseball career is of little to no relevence to those who use his name as it should be, an expletive. Commonly used as an acceptable replacement for the word "fuck" or any swear. Fukudome, and Kosuke can be used in many ways, such as shortened versions down to "fuku".
Example 1:
Guy 1: "Man, that test was horrible, I studied a lot but I'm not sure if I did well."
It's persian (farsi) for Pimp but it has taken another tone in a common vocabulary. It can be used to replace fucker, asshole, buddy, bro. It all depends of how you use it. It can be a friendly word or a very nasty one depending to the way it is used. It's as powerful as the word fucker.
example 1 :
hey koskesh, you were supposed to call me what happened?
example 2:
that koskesh will get what he deserves
example 3:
Don't do business with that koskesh, he would sell his own mom for a buck