The word Thism is misspelled against Theism, meaning "Belief in God."
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Word contains consecutive vowels 'EI' in between alphabets th & sm is misspelled as 'I' as letter 'E' is phonetically ignored
Wrong Spelling:  th-i-sm 
Correct Spelling:  th-ei-sm 
Find more wrongly spelled words of Theism to spell it well.