Bottle-fed is the past form of bottle-feed, and it is also used as an adjective. A bottle-fed baby — or a bottle-fed lamb, calf, or kitten — is one that was given milk from a bottle, not fed from the mother’s breast. Parents use it for human babies; farmers and vets use it for young animals whose mother cannot feed them. Though actually, the word only tells you the milk came from a bottle. The bottle might hold formula from a shop, or milk that was pumped first; it does not, by itself, say which. In everyday talk it often stands as the pair of breastfed.