12 CFR 161.43: Savings association.

The term savings association means a savings association as defined in section 3 of the Federal Deposit Insurance Act, the deposits of which are insured by the Corporation. It includes a Federal savings association or Federal savings bank, chartered under section 5 of the Act, or a building and loan, savings and loan, or homestead association, or a cooperative bank (other than a cooperative bank which is a state bank as defined in section 3(a)(2) of the Federal Deposit Insurance Act) organized and operating according to the laws of the state in which it is chartered or organized, or a corporation (other than a bank as defined in section 3(a)(1) of the Federal Deposit Insurance Act) that the Board of Directors of the Federal Deposit Insurance Corporation and the Comptroller jointly determine to be operating substantially in the same manner as a savings association.