Metaphysical literally means: "after the physics".
It is a supernatural concept, as it deals with things that are not known to physics or the physical senses.
Examples of metaphysical ideas include: the spirit world; the astral plane; the soul; a mind that is separate from the brain; vital life forces or a universal energy: Chi, Prana etc.
Metaphysical ideas are prevalent in the world of alternative medicine, the paranormal, religion, new age mysticism and spiritualism.
Although by definition something metaphysical cannot be sensed, there are many who claim to be able to sense and channel metaphysical healing energy, for example.
NOTE: philosophical metaphysics is different to the meaning given here. It is more concerned with such things as free will, the fundamental nature of reality etcetera.