I'm trying to explain the difference to a group, but cannot describe it myself.
Any analogy or anecdote will also help, in addition to the defining differences.
Metaphysics is philosophical: it’s about explaining the fundamental nature of the world and what it means as humans to inhabit it. Spirituality, on the other hand, is experiential, and has more to do with spiritual practices and the development and discovery of the self.
"Metaphysical" is anything having to do with "metaphysics." "Metaphysics" is the branch of philosophy concerned with explaining the fundamental nature of being and the world. In other words, it is trying to explain fundamental notions by which people understand the world including existence, the definition of object, property, space, time, causality, and possibility.
"Spiritual" refers to anything having to do with the "spirit", and refers to things that are intangible, but are spirit and soul. "Spiritual" may refer to abstract ideas like Love, hate, as well as spirit, soul, or faith, etc.
Metaphysics and spirituality both deal with reality: that which is beyond the physical, the source of the universe. Reality, being permanent, is forever, whereas the physical world is time bound and impermanent.
Metaphysics looks at this subject logically without involving emotions or faith. It is more scientific in its approach than spirituality.
Spirituality is devotional and experiential. It accepts testimony of known enlightened people. Spirituality, in comparison to religion, is free flowing, more tolerant, open to relevant and related thoughts from all faiths and beliefs.
To sum up: metaphysics is purely knowledge based, while spirituality combines knowledge with devotion.
Metaphysics deals with the behavior of the non-physical world. Spirituality describes the behavior of a person with regards to this world.
Metaphysics gives a framework of the non-physical world to base our spiritual conduct off of. It relates to spirituality as physics does to ethics.