An Etymological Dictionary of Astronomy and Astrophysics

1. The beliefs, ideas, or mode of thought of mystics.
   

2. A doctrine of an immediate spiritual intuition of truths believed to transcend ordinary understanding, or of a direct, intimate union of the soul with God through contemplation or ecstasy.
   

3. Obscure thought or speculation (Dictionary.com).

See also: → mystic; → -ism.