The word "significator" is an old-school tarot word. It means a card that signifies a particular person.
Significators are used in many ways. Beyond tarot divination, significators can help you understand and shape your personal identity.
Years ago, a significator was a tarot card chosen by the reader to represent the person for which they were reading. The significator was usually a Court card, and was usually chosen based on age, gender and appearance.
The significator would be chosen and placed on the table. Energetically, this may have been thought to attract the correct cards. The spread was drawn at random as usual.
In other methods of reading, the significator is used to determine which cards will supply the reading. For instance, in the Opening of the Key method, the significator is chosen and then placed back into the deck. After shuffling, the deck is broken into four piles. The pile in which the significator lands is the pile that will provide the reading.
In many modern tarot reading techniques, the significator is simply a position in a tarot spread. Whatever card falls into that position will signify who the querent is at that moment. This can be a great way of getting a handle on the current energies of person you are reading for, whether that be a client or yourself.
You can turn that into a fun exercise by asking the cards "Who am I right now?" and simply pulling a card.
Most tarotists also have a card they refer to as their significator. This is the card that they use to represent themselves - it is the card with which they always identify. Sometimes it is a Court card, but sometimes not. It may be a Major Arcana card, or a Pip card.
Many tarotists will also have a significator for each close friend and family member.
Having this sort of personal significator helps each of us understand our identity. Amongst our tarot friends, it helps us introduce ourselves and understand each other.
As I explain in my book, Tarot Tour Guide, we can use personal significators to encourage our own growth, simply by choosing a significator that has the attributes we want to increase within ourselves. By identifying ourselves with that card, we will naturally grow into those attributes.
A significator can be a simple position in a tarot spread, a way of identifying ourselves and our loved ones, a way of understanding ourselves and a way toward healing. As with all things tarot, it runs the spectrum from the mundane to the magickal.