The Collaborative International Dictionary of English v.0.48:

Monosyllabic \Mon`o*syl*lab"ic\, a. [Cf. F. monosyllabique.]
   Being a monosyllable, or composed of monosyllables; as, a
   monosyllabic word; a monosyllabic language. --
   Mon`o*syl*lab"ic*al*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

monosyllabic
    adj 1: having or characterized by or consisting of one syllable

The Devil's Dictionary (1881-1906):

MONOSYLLABIC, adj.  Composed of words of one syllable, for literary
babes who never tire of testifying their delight in the vapid compound
by appropriate googoogling.  The words are commonly Saxon -- that is
to say, words of a barbarous people destitute of ideas and incapable
of any but the most elementary sentiments and emotions.

    The man who writes in Saxon
    Is the man to use an ax on
                                                              Judibras