exception

noun

1. (countable, uncountable)The act of excepting or excluding; exclusion; restriction by taking out something which would otherwise be included, as in a class, statement, rule.

   “the exception of a rule”

2. (countable, uncountable)That which is excluded from others; a person, thing, or case, specified as distinct, or not included.

   “That rule is usually true, but there are a few exceptions.”

   “The Thirteenth Amendment to the U.S. Constitution had abolished slavery but allowed one major exception: slavery remained appropriate as punishment for a crime.”

3. (countable, uncountable)An objection, on legal grounds; also, as in conveyancing, a clause by which the grantor excepts or reserves something before the right is transferred.
4. (countable, uncountable)An objection; cavil; dissent; disapprobation; offense; cause of offense.
5. (countable, uncountable)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.

   “null pointer exception”

verb

1. (informal, intransitive, rare)To throw an exception.