Someone who is always sucking up to some other person in a sickening manner.
Some one who does anything to get their boss/co-worker/asshole friends to like them. Also someone who should be punched in the jaw.
Ken stays late to work everyday, so he can lick his bosses boots. He is a real ass/butt kisser
a person who smokes a lot of cigarettes in a short time.
tom: wanna go smoke?
mark: we just smoked like 5 min ago. You are such a butt kisser tom.
John; the employee; person who steps in and backdoors other employees, by pampering the president while the assistant to the President is out of town
John the employee, steps in while the assistant is out of town, makes coffee and tea for the President and also supplies her with doughnuts, and in the process, makes other employees, who are also buttkisser, but not "butt kissers" of equal proportion, feel guilty and look bad by not living up to the same buttkissing standards. :-)