The spelling of the word "duby" is not a standard spelling in English. However, it can represent a variant pronunciation of the word "dubious," with the pronunciation /djuːbi/ transcribed in IPA notation. The use of the letter "y" at the end of the word may indicate an attempt to represent the sound of the schwa vowel sound that occurs in unstressed syllables, as in the final syllable of "dubious." It is important to note that this spelling is non-standard and may lead to confusion or misinterpretation.