undefined

Definitions

1. Lacking a definition or value.
   not-comparable
2. indefinite (without limits)
3. That does not have a meaning and is thus not assigned an interpretation.
   not-comparable
4. undefined (lacking a definition)
5. undefined (that does not have a meaning)
6. undecided, uncertain
7. indefinite (which specifies an undetermined object)

Equivalents

Examples

“We slid into our office, past two women discussing the "X factor," an apparently undefined quality their firm felt they lacked.”

“The result⟳ of division by zero is undefined.”

CEFR level