with regard to psychoanalytic theory, the second stage of the oral phase of psychosexual growth, from about the eighth to the eighteenth month of life. During this stage the youth starts to feel which he or she is a sole individual, develops ambivalent outlooks in the direction of the mother, and expresses hostility by biting her breast or the nipple of the bottle. In later life the impulse to bite might take on the form of spitting, chewing on gum or pencils, sticking out one's tongue, or nail-biting. Commonly referred to as oral-sadistic stage.