The main purpose of a dictionary is to give information about words. One looks with some "word" in mind and either finds it exists by noting a boldface alphabetical entry for it; or, not finding it, concludes it does not exist. The latter conclusion is dangerous since the chosen dictionary may have elected to regard the word as too rare or obscene, it may have been missed, or the word sought is too new. There seems little excuse, however, for not listing words that in fact are given in boldface in the work. As this list proves, there are probably more words in your dictionary than you ever imagined.
Beaman, Ralph G.
"Hard-to-Find Words in Web 3 (A-D),"
Word Ways: Vol. 8
, Article 2.
Available at: http://digitalcommons.butler.edu/wordways/vol8/iss3/2