What is "sampajanna"

Sampajañña ( Pāli; Skt.: saṃprajanya) means "clear comprehension", "clear knowing," "constant thorough understanding of impermanence", "fully alert" or "full awareness", as well as "attention, consideration, discrimination, comprehension, circumspection".

Sampajañña is a Pali term used in the suttas; the equivalent Sanskrit term samprajaña is found in Sanskrit texts employed (in translation) by a variety of meditation teachers such as Zen master Thich Nhat Hanh and in the Tibetan tradition.