[mys.ti.cism] n (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