Breastfeeding is an essential aspect of nurturing a newborn. However, there are instances when breastfeeding is not possible or not preferred. In such cases, there are several antonyms for the term 'breastfeed' that can come handy. One of the most common antonyms is 'bottle-feed.' Bottle-feeding is when the baby is given milk or formula from a bottle. Another antonym for breastfeeding is 'wean.' Weaning refers to the process of introducing solid food to a baby as they grow older and their nutritional requirements change. Finally, 'starve' can also be considered an antonym of breastfeeding when the baby is neglected, and adequate nutrition is not provided. However, this is a severe term and should not be used in regular conversation.