The meaning of UNDEFINED is not defined. How to use undefined in a sentence. Undefined definition: without fixed limits; indefinite in form, extent, or application.. See examples of UNDEFINED used in a sentence. Undefined means not defined or made clear, or indefinite in form or extent. Find the pronunciation, translation, and thesaurus of undefined and related words. Definition: - Not having a specific meaning or value. Example: - The variable x is undefined .
