SAT GRE TOEFL onus Definition A burden or responsibility for something. Example "The onus is on the defense to prove the accused's innocence." Sign in to save SAT PDF — $25 GRE PDF — $25 TOEFL PDF — $25 ← onslaught ooze → Study tips featuring "onus" 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