The word Mastres is misspelled against Mastress, a noun meaning "Mistress."
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Mastress has double 'ss' in the end mispronounced as 's'
Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  mastre-s 
Correct Spelling:  mastre-ss 
Explore spell check of Mastress to spell without errors.