1.
a financial organization in the United Kingdom that pays interest on savings accounts, lends money for buying and improving houses, and provides other banking services
2.
a financial institution in the U.K. similar to a savings and loan association
3.
a financial organization in the UK in which people invest money to earn interest, and from which they can borrow money to buy a house or flatA building society is similar to a bank but all its customers have a share in owning it.