Auxiliary and Complementary

Auxiliary

Auxiliary adjective - Available to supply something extra when needed.
Usage example: the auditorium has an auxiliary cooling system used only on particularly sweltering days

Complementary is a synonym for auxiliary in supplementary topic. In some cases you can use "Complementary" instead the word "Auxiliary" as an adjective or a noun.

Complementary

Complementary adjective - Related to each other in such a way that one completes the other.

Auxiliary is a synonym for complementary. You can use "Auxiliary" instead the word "Complementary" as an adjective or a noun.

Cite this Source
Complementary and Auxiliary. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/auxiliary/complementary
Auxiliary & Complementary. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/auxiliary/complementary>.
Complementary or Auxiliary. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/auxiliary/complementary.
Google Ngram Viewer shows how "auxiliary" and "complementary" have occurred on timeline