Longstanding
Longstanding adjective - Having existed for a long time.
Undefined and longstanding are semantically related. In some cases you can use "Undefined" instead an adjective "Longstanding".
Undefined
Undefined adjective - Not seen or understood clearly.
Longstanding and undefined are semantically related. Sometimes you can use "Longstanding" instead an adjective "Undefined".
Mutual synonyms
Cite this Source
Undefined and Longstanding. (2016). Retrieved 2026, July 22, from https://thesaurus.plus/related/longstanding/undefined
Longstanding & Undefined. N.p., 2016. Web. 22 Jul. 2026. <https://thesaurus.plus/related/longstanding/undefined>.
Undefined or Longstanding. 2016. Accessed July 22, 2026. https://thesaurus.plus/related/longstanding/undefined.
Google Ngram Viewer shows how "longstanding" and "undefined" have occurred on timeline