Noun
1. a very young child (birth to 1 year) who has not yet begun to walk or talk;
"isn't she too young to have a baby?"2. sometimes used as a term of address for attractive young women
3. a very young mammal;
"baby rabbits"4. the youngest member of a group (not necessarily young);
"the baby of the family""the baby of the Supreme Court"5. an immature childish person;
"he remained a child in practical matters as long as he lived""stop being a baby!"6. a project of personal concern to someone;
"this project is his baby"