Webster's Tenth Collegiate dictionary lists synonyms of headword adjectives in two ways: in small caps in the main definition set, and at the end with the heading syn followed by a group of additional small cap synonyms. Approximately 220 of the headword adjectives merit the syn treatment, and the one thousand synonyms they dissect represent about one-sixth of the headword adjectives.
Eckler, A. Ross
Word Ways: Vol. 43
, Article 8.
Available at: http://digitalcommons.butler.edu/wordways/vol43/iss1/8