all realisable assets provided under a pledge (including money provided under a pledge), a repurchase or similar agreement, or otherwise, for the purpose of securing rights and obligations potentially arising in connection with a system, or provided to central banks of the Member States or to the future European central bank, a security which a debtor gives his creditor to guarantee the performance of his obligation; it usually consists of a mortgage,a transfer of property,securities, collateral, collateral security - a)American expression used to describe a security put up by a borrower in addition to this promise repay; b)the precise English definition is a security put up by someone other than the borrower,either in support of the guarantee or as a third party security in place of the guarantee