In Language on Vacation, Dmitri Borgmann highlighted the 13-letter GIBBLEGABBLED and HIGGLEHAGGLED as the longest words with all their letters drawn from the first half of the alphabet, A-M. He also referred to the 11-letter NONSUPPORTS as the longest word with all of its letters drawn from the second half of the alphabet, N-Z.
"Words in Windows,"
Word Ways: Vol. 35
, Article 6.
Available at: https://digitalcommons.butler.edu/wordways/vol35/iss2/6