(1) One of the five ever-functioning subsidiary awarenesses (mental factors) that takes an uncommon characteristic feature of the appearing object of a non-conceptual cognition or a composite feature of the appearing object of a conceptual cognition, and ascribes a conventional significance to it, different from that of everything else that appears in the background within that cognition. It does not necessarily ascribe a name or mental label to its object, nor does it compare it with previously cognized objects, as the word "recognition," with which it is often translated, implies. (2) Distinguishing an object as being something specific – such as, when studying the Dharma, oneself as being a sick person, one's spiritual teacher as being a doctor, and the Dharma as being medicine.
Tibetan: འདུ་ཤེས། 'du-shes
J. Hopkins: Discrimination