Nirvikalpa samādhi, absorption free of conceptual distinctions, is used especially in Advaita Vedānta for the state in which the mind is wholly absorbed in Brahman and no distinction of knower, knowing and known remains. It is contrasted with savikalpa samādhi, in which such distinctions persist. Modern teachers such as Ramakrishna spoke of it often.
Nirvikalpa samādhi
Absorption without mental constructs, in which the distinction of knower and known disappears.
Also: Nirvikalpa samadhi