The word Trepaner is misspelled against Trepanner, a noun meaning "One who trepans."
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Trepanner has double "nn" is mispronounced as "n"
Remember double 'NN' in between the strings trepa & er which should not be misspelled with single 'N'
Wrong Spelling:  trepa-n-er 
Correct Spelling:  trepa-nn-er 
Explore spell check of Trepanner to spell without errors.