The following 11-by-11 word square appears in Language on Vacation (Scribner's, 1965), and is described by the author, Dmitri Borgmann, as 'quasi square'. The seven central words are of impeccable quality, but the two sets of letter combinations at each end are complete gibberish.
Word Ways: Vol. 20
, Article 2.
Available at: http://digitalcommons.butler.edu/wordways/vol20/iss2/2