- 27 total number
Honorificabilitudinitatibus, at 27 letters long, is the longest English word consisting strictly of alterating consonants and vowels. It means "With honorableness" (a nonsense word from medieval literature) Eighteen letter words with this property include epicoracohumeraler and myelocytomatosises. A seventeen letter word with this property is hypovitaminosises. Sixteen letter words with this property include aluminosilicates, depolarizability, and supererogatorily. Fifteen letter words with this property include cytomegalovirus, heterozygosises, hexosaminidases, paramyxoviruses, pararosanilines, parasitological, tenosynovitides, tenosynovitises, unimaginatively, and verisimilitudes.