an infant or very young child.

a newborn or very young animal.

the youngest member of a family, group, etc.

an immature or childish person.

a human fetus.

Informal .

Sometimes Disparaging and Offensive . a girl or woman, esp. an attractive one.

a person of whom one is deeply fond; sweetheart.

( sometimes initial capital letter ) an affectionate or familiar address (sometimes offensive when used to strangers, casual acquaintances, subordinates, etc., esp. by a male to a female).

a man or boy; chap; fellow

He's a tough baby to have to deal with.

an invention, creation, project, or the like that requires one's special attention or expertise or of which one is especially proud.

an object; thing

Is that car there your baby?

of or suitable for a baby

baby clothes.

of or like a baby; infantile

baby skin.

small; comparatively little

a baby car.

treating babies

a baby doctor.

to treat like a young child; pamper.

to handle or use with special care; treat gently.

adjective

grown-up , mature

adjective

baby , childish , foolish , immature , infantile , juvenile , kid stuff , puerile , silly , sissy , spoiled , cherubic , childlike , infantine , simple