In a sentence
His expertise in the field was indubitable, recognized by peers worldwide.
Synonyms
undeniableunquestionablecertainindisputable
Antonyms
doubtfulquestionable
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See all More GRE words starting with I
iconoclast
a person who attacks cherished beliefs or established institutions
iconoclastic
attacking or undermining traditional beliefs and institutions
idiosyncrasy
a peculiar habit or feature distinctive to an individual
idolatrous
excessively or blindly devoted to something or someone
idolatry
extreme admiration or worship of someone or something, often to an excessive degree
idolize
to admire or revere someone to an excessive degree
idyllic
charmingly peaceful and free of trouble
ignoble
lacking nobility of character; dishonorable
Learn words the way the GRE tests them.
Vocabulary sticks when you meet it in real sentences. Practise these words inside text completion and sentence equivalence questions.