Verified against
- University Word List (Xue & Nation 1984)Authoritative
- Academic Word List (Coxhead 2000)Authoritative
- CEFR-J v1.5 + Octanove C1/C2Authoritative
- New General Service List (Browne et al. 2013)Authoritative
- Open English WordNet 2024Authoritative
Each source is a real, checkable word list that contains assure. We never claim an official exam-board list — none is published for the GRE, GMAT, or SAT.