noun: (military) Initialism of unauthorized absence.
noun: (countable, UK, government) Initialism of unitary authority. [In local government, a single-tier authority which replaces a two-tier structure. For example, in England, county councils are abolished and their responsibilities are transferred to boroughs and local government districts (but this only applies to some counties, not all). In some cases complete counties, such as Cornwall and Northumberland, are now unitary authorities without any subdivision into local government districts.]
noun: (countable, computing) Initialism of user agent. [(computing) A client application used by an end user, typically for a network protocol such as HTTP or FTP.]
