Weaning is the process of switching a baby from breast-feeding to bottle-feeding, from breast- or bottle-feeding to a cup, or breast- or bottle-feeding to solid foods.
Weaning may take a few months or more than a year. It begins when a baby starts eating solid foods, at about 4 to 6 months of age. It ends when the child no longer breast-feeds or takes a bottle.
WebMD Medical Reference from Healthwise