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.n. An infant; a weanling.n. A child; a boy or girl of tender age.