Section 1. As used in this chapter, the following words shall, unless the context otherwise requires, have the following meanings:?
''Bank'', an association or corporation chartered by the commonwealth under chapter 168, 170 or 172.
''Board'', the board of trustees or directors, as the case may be, in a bank.
''Capital stock'', the sum of the par value of the preferred and common shares of capital stock of a trust company, issued and outstanding.
''Commissioner'', the commissioner of banks.
''Federally chartered bank'', a national banking association, federal savings and loan association, federal savings bank or federal credit union authorized to do business in the commonwealth.
''Stock corporation'', an association or corporation chartered by the commonwealth under the provisions of chapter 168 or 170, which has converted to a stockholder form of corporation, or a trust company as defined in chapter 172.
''Surplus account'', an account so designated on the books of a bank and consisting of amounts required by law.
''Thrift Institution'', an association or corporation chartered by the commonwealth under chapter 168 or 170 which is in mutual form.