The Collaborative International Dictionary of English v.0.48:

Neologism \Ne*ol"o*gism\, n. [Cf. F. n['e]ologisme.]
   1. The introduction of new words, or the use of old words in
      a new sense. --Mrs. Browning.
      [1913 Webster]

   2. A new word, phrase, or expression.
      [1913 Webster]

   3. A new doctrine; specifically, rationalism.
      [1913 Webster]

WordNet (r) 3.0 (2006):

neologism
    n 1: a newly invented word or phrase [syn: neologism,
         neology, coinage]
    2: the act of inventing a word or phrase [syn: neologism,
       neology, coinage]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "neologism":
   Young Turk, arriviste, blend, breakthrough, bright young man,
   coinage, comer, discovery, fledgling, ghost word, innovation,
   introduction, invention, leap, modern, modern generation,
   modern man, modernist, modernizer, neologist, neology, neonate,
   neoteric, neoterism, neoterist, new generation, new man, new phase,
   new sense, new word, newfangled expression, nonce word,
   nouveau riche, novelty, novus homo, parvenu, portmanteau word,
   rising generation, stripling, upstart