SAT TOEFL supplementary Definition Additional to or serving to complete something. Example "The report includes supplementary data in the appendix." Sign in to save SAT PDF — $25 TOEFL PDF — $25 ← supplement supplicate → Study tips featuring "supplementary" TOEFL Academic Vocabulary: Study by Topic How Context Clues Save You on the SAT Related words SAT antonym SAT abase SAT abdicate SAT abdomen SAT abduction SAT abet SAT abeyance SAT abject SAT abjure SAT ablution SAT abnegate SAT abnormal