Sufi
Part of speech: noun
Definition: a Muslim mystic or ascetic
Example sentence: If you call yourself a singer, then you must have the ability to sing anything, whether it's pop, classical, rock, sufi, or folk.
Mysticism
Part of speech: noun
Definition: The beliefs, ideas, or thoughts of mystics.A doctrine of direct communication or spiritual intuition of divine truth.A transcendental union of soul or mind with the divine reality or divinity.Obscure thoughts and speculations.
Example sentence: Many of my fellow atheists consider all talk of 'spirituality' or 'mysticism' to be synonymous with mental illness, conscious fraud, or self-deception. I have argued elsewhere that this is a problem - because millions of people have had experiences for which 'spiritual' and 'mystical' seem the only terms available.