Verified against
- Open English WordNet 2024Authoritative
- Manhattan Prep 1000 GRE WordsRecognized
- 5000 GRE Words (recognized prep compilation)Recognized
- GRE Word List 4700 (recognized prep compilation)Recognized
- PrepScholar 357 GRE WordsRecognized
- GregMat 960 GRE WordsRecognized
- SparkNotes 1000 SAT WordsRecognized
Each source is a real, checkable word list that contains indefatigable. We never claim an official exam-board list — none is published for the GRE, GMAT, or SAT.