• Wikipedia - baby

An infant or baby is a very young child. The term "infant" derives from the Latin word in-fans, meaning "unable to speak." There is no exact definition for infancy. Quite often babies are called infants until they reach the age of one. However, babies are traditionally called "toddlers" when they start to walk whether or not they have reached their first birthday. Daycares with an "infant room" providing care will call all their children in the infant room "infants" even if they are older than a year and/or walking; they will sometimes use the term "walking infant".