wean

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

• transitive verb To accustom (the young of a mammal) to take nourishment other than by suckling.
• transitive verb To detach from that to which one is strongly habituated or devoted.
• transitive verb To accustom to something from an early age. Often used with on:

from The Century Dictionary.

• To accustom (a child or young animal) to nourishment or food other than its mother's milk; disaccustom to the mother's breast: as, to wean a child.
• To detach or alienate, as the affections, from any object of desire; reconcile to the want or loss of something; disengage from any habit, former pursuit, or enjoyment: as, to wean the heart from temporal enjoyments.
• noun An infant; a weanling.
• noun A child; a boy or girl of tender age.

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

• transitive verb To accustom and reconcile, as a child or other young animal, to a want or deprivation of mother's milk; to take from the breast or udder; to cause to cease to depend on the mother nourishment.
• transitive verb Hence, to detach or alienate the affections of, from any object of desire; to reconcile to the want or loss of anything.
• noun A weanling; a young child.

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

• verb transitive To cease giving milk to an offspring.
• verb transitive To quit from something to which one is addicted or habituated.
• verb intransitive To cease to depend on the mother for nourishment.
• verb intransitive To cease to depend.
• noun Scotland A small child.

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

• verb detach the affections of
• verb gradually deprive (infants and young mammals) of mother's milk