spendthrifts , stretchmarks (2 vowels, 12 letters); farthingsworths , shillingsworths , strengthfulness (3, 15); and handcraftsmanship , splanchnemphraxis (4, 17). The word nth (an unspecified ordinal number ) is the only all-consonant word in many dictionaries. [ edit ] Alternating vowels and consonants The superlatively long word honorificabilitudinitatibus (27 letters) alternates consonants