baby - In basic English usage, an infant is defined as a human child at the youngest stage of life, especially before they can walk or simply a child before the age of one. The term 'infant' derives from the Latin word in-fans, meaning 'unable to speak.' There is no exact definition for infancy. 'Infant' is also a legal term with the meaning of minor; that is, any child under the age of legal adulthood. A human infant less than a month old is a newborn infant or a neonate. The term 'newborn' includes premature infants, postmature infants and full term newborns. Quite often babies are called infants until they reach the age of one. Babies are traditionally called 'toddlers' (generally 12-24 months) when they start to walk, whether or not they have reached this age. Daycares with an 'infant room' often call all children in it 'infants' even if they are older than a year and/or walking; they sometimes use the term 'walking infant'.