GRE TOEFL IELTS questionable Definition Open to doubt or debate; of uncertain quality or legitimacy. Example "His motives for helping were questionable." Sign in to save GRE PDF — $25 TOEFL PDF — $25 IELTS PDF — $25 ← quest questionnaire → Study tips featuring "questionable" TOEFL Academic Vocabulary: Study by Topic Boost Your IELTS Writing With Precise Vocabulary Related words GRE awe GRE smithereens GRE abacus SAT abase GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate SAT abdomen GRE abduct GRE aberrant