The word "overfullnesses" is spelled with three consonants and six vowels, making it a challenging word to spell. According to IPA phonetic transcription, the word is pronounced as /oʊvərˈfʊlnəsɪz/. The root word "overfull" means having more than enough, and "-ness" is a suffix used to denote a state of being. By adding the suffix "-es" to the end of "overfullness," the word becomes plural. Its spelling is a prime example of the complexities of the English language.