To dream that you see the gatekeeper means that you see someone in your life who is looking scary and unknown. Perhaps the gatekeeper is the symbolism of the fears the dreamer has. If you are the one who is the gatekeeper, it means that you are confident enough to control your own and other lives as well. If you are unable to pass the gates because of the gatekeeper, there are barriers in your waking life that must be removed. Please also see the meaning of gate.
Read more about dreaming of Gatekeeper in other dream meanings interpretations.