A flop shot is when the golfer purposely hits the ball high into the air without sending it much distance. Flopping the ball like this became popular with the creation of the 60° wedge and square grooves.
A Perfect Example
A perfect example of a common scenario on the golf course is when a player misses the green with their approach shot. The ball is sitting right off the green, but buried in medium length grass.
When you assess the situation, you notice that the green is a bit elevated above the ball. In addition, a bunker stands in the way. You cannot just hit the ball, as it will fly far over the top and you will face a long comeback putt. The chip shot will fly too low, and travel too far. The pitch shot will fly longer, but may still travel to four.
The only answer? The flop shot! The ball will fly for a short distance, and will barely roll after it lands, which is exactly what you are after.