The moon is said to signify many different things in terms of tarot meanings. Arthur Waite, who is a renowned studier of tarot and other aspects of religion and the occult, has stated that the moon signifies that which gives into our animal nature. The moon card recalls everything within us that is inhuman and animalistic and brings it all to the surface. At the very last instant though, the mind is there to remind us to not let those aspects of ourselves take over, and the animals that were so vexed by the presence of the moon in the first place will begin to sink back down to the place that they came from originally.
A better way to put that though, or to put it more eloquently so that anyone can understand, is that the moon signifies all that which gives us emotional unrest. When the moon card appears anywhere on a four point spread when someone is being given a tarot reading, wherever this card is placed is usually a very emotionally sensitive spot for the person who is being read. Let's take a look at some of the areas where the moon might have a more specific interpretation.
If the moon card were to appear in the area of a four point spread having to do with relationships, then this would mean that your relationship is at a very torrential point. This is not of course to indicate the status of the relationship itself, but your own views on the relationship. Therefore, if you receive the moon card, it does not mean that your entire relationship is at a place of unrest, it means that you are at a place of unrest within your relationship that will soon be quelled with the passage of time. Do not make any rash decisions during this emotionally sensitive period or you will probably regret them.
If you happen to see the moon card appearing in the area that tells of your financial issues, then this means that you are having mixed feelings about your money. This may indicate that you are overly stressed and concerned about spending, or that you have been too liberal with your cash. Either way, the moon card reminds you to take a step back and really consider what is important and what needs and does not need to have money spent on it.
If this card appears on the area that dictates how you are feeling about your career, then what this means is that you are probably feeling at odds with your career. Maybe you are at a point in your life where you are trying to decide whether what you are doing now is what you want to do for the rest of your life or not. Well, because the moon card only indicates a temporary period of madness, make sure not to make too many crazy decisions early on or else you might regret giving up your cushy job for one that you do not appreciate very much.
Finding the moon card on the area which speaks of physical health and happiness probably means you are having ups and downs emotionally. You are feeling happy and healthy one minute, and gloomy and ill the next. Keep in mind that this state is largely mental, and you will not have to deal with it forever. Sooner or later you will come out the victor in this case.