Definition - What does Thoughtlessness mean?
Thoughtlessness is a state in which the mind contains no thoughts, no preconceptions and is, therefore, fully aware in the spiritual sense. It is a concept in Hindu, yoga and Buddhist philosophy.
Thoughtlessness is sometimes associated with nirvikalpa, in which the mind is beyond thinking and has no logical thoughts or thought form. Nirvikalpa samadhi is the blissful state in which thoughts cease to exist. Samadhi is the eighth and final limb of Patanjali's eight-fold path of yoga as described in The Yoga Sutras.
Yogapedia explains Thoughtlessness
In its everyday form, the mind is cluttered with many thoughts which distract and prevent the yogi from achieving a calm, higher state of consciousness. Through yoga, the yogi learns to un-clutter his/her mind, reaching a state of ekagra, when the mind is one-pointed with a single focus. At this stage, the mind is able to gain deeper insight into the single thing on which it is focused.
From a single thought, the mind transforms further, reaching its highest potential in a state of thoughtlessness, or thoughtless awareness. Unencumbered by attachment to thoughts, the yogi is able to grow spiritually.