a foolish oaf; a goofyperson. : Don't be a goof. Get with it.
to use heroin or some other addictive drugs without intending to become addicted; to play around (with heroin). (Drugs.) : Gert spent the first few years just goofing.
to scratch, nod, and slobber after an injection of heroin. (Drugs.) : She has been goofing for an hour.
and goof up. to make a blunder. : This time, you goofed. , I'm afraid I goofed up.
a blunder; an error. : This goof is yours, not mine.