The word Thesari is misspelled against Thesauri, which is plural of "Thesaurus"
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Word contains consecutive vowels 'AU' in between alphabets thes & ri is misspelled as 'A' as letter 'U' is phonetically ignored
Wrong Spelling:  thes-a-ri 
Correct Spelling:  thes-au-ri 
Find more wrongly spelled words of Thesauri to spell it well.