'clarity of consciousness', clear comprehension. This term is frequently met with in combination with mindfulness (sati). In D. 22, M. 10 it is said: "Clearly conscious is he in going and coming, clearly conscious in looking forward and backward, clearly conscious in bending and stretching his body; clearly conscious in eating, drinking, chewing and tasting, clearly conscious in discharging excrement and urine; clearly conscious in walking, standing, sitting, falling asleep and awakening; clearly conscious in speaking and keeping silent." - For a definition of the term sati-sampajañña, s. Pug. 86.
According to the Com., 'clarity of consciousness' is of 4 kinds: regarding the purpose, the suitability, (inclusion in the meditative) domain, and the undeluded conception of the activity concerned. Explained in detail in Com. to Satipatthāna Sutta. (tr. in The Way of Mindfulness, by Soma Thera; BPS).