exception
n//əkˈsɛpʃən//undantag
The act of excepting or excluding; exclusion; restriction by taking out something which would otherwise be included, as in a class, statement, rule.
That which is excluded from others; a person, thing, or case, specified as distinct, or not included.
(programming) An interruption in normal processing, typically caused by an error condition, that can be raised ("thrown") by one part of the program and handled ("caught") by another part.