A Slap On The Wrist ( a slight punishment ... )
A slap on the wrist is a punishment that is very mild. Example:"He should be in jail for what he did, but he got off with just a slap on the wrist."
When the punishment turns out to be less than was expected, it is considered a slap on the wrist. Criminals would be very happy to get a slap on the wrist instead of several years in jail. A businessman would be happy to get a slap on the wrist after making a serious error that cost his company a significant sum of money.
buy a lemon.....To buy something that proves to be worthless.
For example:"That car he bought is a real lemon."
