Simple Definition of unfathomable
: impossible to understand
Examples of unfathomable
His behavior is completely unfathomable.
<the unfathomable reaches of space>
First Known Use of unfathomable
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Thesaurus: All synonyms and antonyms for "unfathomable" Nglish: Translation of "unfathomable" for Spanish speakers Britannica English: Translation of "unfathomable" for Arabic speakers
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