Today is not really a word, but more of a tradition. Military members the world over wear most of their medals and decorations on the left side of their chest. Why is that?

This custom seems to have originated during the times of the crusades. Christian knights were sometimes given awards for valor, devotion, and bravery. These were hard awards to win and were prized by the winner. The knight who won an award would wear his award over his heart to keep it close to him.

Since the knight wore his award fixed to his armor he would want and need to also protect it during battle. Since the shield was carried with the left arm the awards were sheltered during battle and thus kept safe.
Many customs concerning the left side versus the right side were formed during the crusades. Mounting a horse can actually be done on either side. However custom says mount on the left side. Why? The sword is carried on the left side. This is claimed to be the reason for driving on the left side of the rode. So a knight could draw his sword at a possible enemy who would then be on his right side.

Saluting came about because of this. It was a way to show another knight that your right hand was free and he was safe to pass. Approaching knights would raise their visors with their right hand as they would approach one another. Then hold their empty open right hand against their head while they passed.

The customs of passing right sides has continued to this day, as well as saluting and wearing your decorations on the left. I know this was a little off the Naval line, but it all comes back one way or another.