What is Asset Specificity?

Legal Definition
Asset specificity is a term related to the inter-party relationships of a transaction. It is usually defined as the extent to which the investments made to support a particular transaction have a higher value to that transaction than they would have if they were redeployed for any other purpose. Asset specificity has been extensively studied in a variety of management and economics areas such as marketing, accounting, organizational behavior and management information systems.
-- Wikipedia
Legal Definition
An asset's feature making it useful for a special purpose. It cannot be sold in a firesale.