Mathematics

• Undefined (mathematics), with several related meanings Indeterminate form, in calculus

Computing

• Undefined behavior, computer code whose behavior is not specified under certain conditions

• Undefined value, a condition where an expression does not have a correct value

• Undefined variable

• Undefined, a function or variable lacking a declaration

• Undefined, a variable lacking initialization

• Undefined, an unavailable linker symbol (function, or global variable)

Other uses

• Undefined, something that lacks definition

• Undefined citizenship, a post-Soviet form of statelessness in Estonia

See also

• Null (disambiguation)

• Void (disambiguation)

• Invalid (disambiguation)

• Definition (disambiguation)

• Definable (disambiguation)

• All pages with titles beginning with Undefined