Tucked away below the line in Webster's Second Edition is the word KJOEKKENMOEDDING, a Danish word from which kitchen midden is derived. This word is one of the very few beginning with the letters KJ which are listed by English dictionaries. Apart from this, the word is also notable for its two pairs of like letters, i.e. its pair of adjacent K's and its pair of adjacent D's.
"Words With Two Pairs of Like Letters,"
Word Ways: Vol. 6
, Article 6.
Available at: http://digitalcommons.butler.edu/wordways/vol6/iss1/6