To strike someone with a foreign, hard plastic object. A bonk will usally result in a loud "crack" if performed corectly. A well place hit on the elbow, head (skull), knee, or spine will result in a red inflammed welt which will be sensitive to the touch for hours.
"Yesterday Jeff bonked Bert in the side on the head with his nalgene in the hall"
"If you you don't shut your fucking mouth im going bonk you with this broken "bop it" i got a garage sale last week!!
A dumb, un-employed, lazy person who sits around the house all day and waits for phone calls from his "friends" who actually have lifes and are working or going to school. A dunk is usally a male ranging from the ages of 18-25 who crawls out of bed around 1:00 in the afternoon after a night of pointless binge drinking.
"Holy fuck Gordan is such a fuckin' dunk!!"
"Man your bro is the biggest dunk, he needs to get a job and figure his life out!"