Merriam-Webster Collegiate Dictionary - mysticism

 noun  Date: 1736  1. the experience of mystical union or direct communion with ultimate reality reported by mystics  2. the belief that direct knowledge of God, spiritual truth, or ultimate reality can be attained through subjective experience (as intuition or insight)  3.  a. vague speculation ; a belief without sound basis  b. a theory postulating the possibility of direct and intuitive acquisition of ineffable knowledge or power