The verb to lose means something has gone missing. Maybe it's your car keys. Maybe it's points in a game. Maybe it's the love of your life. Sorry about that.
You can physically lose something by misplacing it, or you can lose your pride in a competition. You can lose a game, you can lose your library book, you can lose money, you can lose your business, you can lose sight of your child, you can even lose your mind — basically, you can lose just about anything. Losing something is usually not a good thing, unless it's that annoying boyfriend or weight.