baby

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A very young child; an infant.
• noun An unborn child; a fetus.
• noun The youngest member of a family or group.
• noun A very young animal.
• noun An adult or young person who behaves in an infantile way.
• noun A lover or sweetheart.
• noun Sweetheart; dear. Used as a term of endearment.
• noun Slang An object of personal concern or interest.
• adjective Of or having to do with a baby.
• adjective Infantile or childish.
• adjective Small in comparison with others of the same kind.
• transitive verb To pamper like a baby; coddle. synonym: pamper.

from The Century Dictionary.

• noun An infant or young child of either sex; a babe.
• noun A doll.
• noun [Cf. E. pupil, ⟨ L. pupilla, a girl, the pupil of the eye.] The minute reflection which a person sees of himself in the pupil of another's eye.
• noun One who is like a baby; a childish person.
• noun To attempt to excuse excessive or feigned ignorance or stupidity on the ground of professed inexperience. [Colloquial in both uses.]
• Babyish; infantine; pertaining to an infant.
• Small, or comparatively small: as, a baby engine.
• To treat like a young child.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Pertaining to, or resembling, an infant; young or little.
• transitive verb To treat like a young child; to keep dependent; to humor; to fondle.
• noun An infant or young child of either sex; a babe.
• noun A small image of an infant; a doll.
• noun the minute reflection which one sees of one's self in the eyes of another.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A very young human, particularly from birth to a couple of years old or until walking is fully mastered.
• noun Any very young animal, especially a vertebrate; many species have specific names for their babies, such as kittens for the babies of cats, puppies for the babies of dogs, and chicks for the babies of birds. See Category:Baby animals for more.
• noun A person who is immature or infantile.
• noun A term of endearment for a girlfriend or boyfriend or spouse.
• noun informal A form of address to a man or a woman considered to be attractive.
• noun A pet project or responsibility.
• noun The lastborn of a family; a benjamin.
• noun An affectionate term for anything.
• adjective Of a child: very young; of the age when he or she would be termed a baby or infant.
• adjective Of an animal: young.
• adjective Intended for babies.
• adjective etc. Picked when small and immature (as in baby corn, baby potatoes).
• verb To coddle.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (slang) sometimes used as a term of address for attractive young women
• noun a project of personal concern to someone
• noun a very young mammal
• noun an unborn child; a human fetus
• noun an immature childish person
• noun the youngest member of a group (not necessarily young)
• verb treat with excessive indulgence
• noun a very young child (birth to 1 year) who has not yet begun to walk or talk