cern-, cert-, cer-; cret-, creet-, cre-

(Latin: to separate, to sift, to distinguish, to understand, to decide, to determine; separated, separation, to set apart; the glandular extraction or the movement out of a natural substance)

Used to express the ability a person has to distinguish, or to perceive, something with the eyes and the mind. Related to crit-; as in criticize, diacritical, critique, etc.