NOUN (2)

1. any artificially elegant style of language;

2. an elegant style of prose of the Elizabethan period; characterized by balance and antithesis and alliteration and extended similes with and allusions to nature and mythology;

The Collaborative International Dictionary of English v.0.48:

euphuism \eu"phu*ism\ ([=u]"f[-u]*[i^]z'm), n. [Gr. e'yfyh`s
   well grown, graceful; e'y^ well + fyh` growth, fr. fy`ein to
   grow. This affected style of conversation and writing,
   fashionable for some time in the court of Elizabeth, had its
   origin from the fame of Lyly's books, "Euphues, or the
   Anatomy of Wit," and "Euphues and his England."] (Rhet.)
   An affectation of excessive elegance and refinement of
   language; high-flown diction.
   [1913 Webster]

WordNet (r) 3.0 (2006):

euphuism
    n 1: any artificially elegant style of language
    2: an elegant style of prose of the Elizabethan period;
       characterized by balance and antithesis and alliteration and
       extended similes with and allusions to nature and mythology