Samadhi
समाधि (samādhi)
Complete absorption - the settling of attention so total that the sense of a separate observer goes quiet.
Samadhi is built from roots meaning to place together: a gathering of the scattered self into one place. In Patanjali's yoga it is the eighth and final limb, the fruition of the whole discipline; in Buddhist usage it often names deep concentration more broadly.
Descriptions vary by school, but converge on one report: in samadhi the usual threefold structure of experience - knower, knowing, known - simplifies. The commentator in the head does not describe the moment because it is no longer standing apart from it.
The traditions are careful here: samadhi is not the goal dressed in Sanskrit, but a doorway. States pass. What matters is what remains changed in the person who returns - less grasping, cleaner seeing, a steadier kindness.