Hugo Brandt Corstius has proposed the name oligosyllabic for a word in which the number of letters is more than four times the number of syllables, and hypersyllabic for a word in which the number of letters is less than twice the number of syllables. Oligosyllabic and hypersyllabic words exist for most word lengths, but they are increasingly rare with increasing word length-infact, no Merriam-Webster hypersyllabic words of more than 21 letters or oligosyllabic words for more than 19 letters are known to exist. This is in contrast with the Dutch experience reported by Corstius in the August Word Ways in which words exist up to 24 and 29 letters, respectively.
Eckler, A. Ross
Word Ways: Vol. 36
, Article 22.
Available at: http://digitalcommons.butler.edu/wordways/vol36/iss4/22