Definition - The definition is a game in the olympics in Ancient Greece composed of discus-throwing, the long jump, javelin-throwing, running, and wrestling.
The public was not very interested in this sport, so the prize-money for the entire pentathlon was less than for the stadion or wrestling.
Rules - In order to have a chance to be crowned a victor, the competitors have to do well in all of these sports.
How is it similar to today? - All of the sports in the pentathlon are similar to the sports today, but there are some differences. In the ancient long-jump, contestants used jumping-weights. Also, javelin-throwing is similar, but in the ancient game there was a leather loop that was attached to the javelin shaft to add spin and secure a steadier flight.