The word Septenial is misspelled against Septennial, meaning "Recurring every seven years."
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Septennial has double "nn" is mispronounced as "n"
Remember double 'NN' in between the strings septe & ial which should not be misspelled with single 'N'
Wrong Spelling: septe-n-ial
Correct Spelling: septe-nn-ial
Find more wrongly spelled words of Septennial to spell it well.