In the November 2001 Kickshaws, an ambidextrous word is defined as one whose first half contains only letters from the first half of the alphabet, and whose second half contains letters from the second half of the alphabet. An antidextrous word is defined the other way round. In the following, words of even length only are considered, to avoid the problem of the central letter in words with an odd number of letters.
"Ambidextrous and Antidextrous Words,"
Word Ways: Vol. 39
, Article 18.
Available at: http://digitalcommons.butler.edu/wordways/vol39/iss2/18