Answer:
A graceful loser is a person that takes a loss "on the chin" and does not act bitter, but instead congratulates the winner in a non-malicious manner.
For example, if a player loses a tennis match and is quite happy to go across the court to shake the hands of his opponents, wish him well and walk away, then he is a graceful loser.
On the other hand, a person who loses in a less than dignified manner is a person that throws tantrums, complains, or rejects the result of a match because he feels he was treated unfairly or his opponent did not deserve the win.
An example is a tennis player attacking the umpire, shouting and rejecting the outcome because he feels some of the umpire's calls were wrong and his opponent was lucky to win
