Rigpa

In Dzogchen teaching, rigpa (; Skt. vidyā; "knowledge") is the knowledge of the ground. The opposite of rigpa is marigpa (avidyā, ignorance).
Definition.
"Rigpa" is the knowledge of the ground. It has also come to mean the "pristine awareness" that is the fundamental ground itself. Erik Pema Kunsang translates a text which provides basic definitions of rigpa and marigpa in a Dzogchen context:
Rigpa has two aspects, namely "kadag" and "lhun grub". "Kadag" means "purity" or specifically "primordial purity". "Lhun grub" in Tibetan normally implies automatic, self-caused or spontaneous actions or processes. As quality of "rigpa" it means "spontaneous presence" It may also mean "having a self-contained origin", being primordially Existent, without an origin, self-existent. This division is the Dzogchen-equivalent of the more common Mahayana wisdom and compassion division.
Practice.
Dzogchen practices aim to attain rigpa and integrate this into everyday life:
The Menngagde or 'Instruction Class' of Dzogchen teachings are divided into two parts: "Trekchö" and "Tögal" (thod rgal). Ron Garry: 
In Dzogchen, a fundamental point of practice is to distinguish rigpa from sems ("citta", (grasping) mind). According to the 14th Dalai Lama, ""sems" is the mind which is temporarily obscured and distorted by thoughts based upon the dualistic perceptions of subject and object." "Rigpa" is pure awareness free from such distortions. "Cittata", the nature of mind, is the inseparable unity of awareness and emptiness, or clarity and emptiness, which is the basis for all the ordinary perceptions, thoughts and emotions of the ordinary mind.
Citing Dodrupchen Jikme Tenpe Nyima, the 14th Dalai Lama states the full measure of rigpa occurs with the third vision.