I don't think you are right Naznatips. If you were, it would absolutely make no sense to use this term because almost every game would be a Dungeon Crawler. In my opinion, a dungeon crawler is a RPG that that focuses COMPLETELY on contained areas where the player proceeds through a dungeon collecting treasure, usually culminating in a boss battle.
As I said, Children of Mana seems to be a good example for my definition, you do almost nothing else than proceeding through dungeons.