The Collaborative International Dictionary of English v.0.48:

Prosody \Pros"o*dy\, n. [L. prosodia the tone or accent of a
   syllable, Gr. ? a song sung to, or with, an accompanying
   song, the accent accompanying the pronunciation; ? to + ?
   song, ode: cf. F. prosodie. See Ode.]
   That part of grammar which treats of the quantity of
   syllables, of accent, and of the laws of versification or
   metrical composition.
   [1913 Webster]

WordNet (r) 3.0 (2006):

prosody
    n 1: the patterns of stress and intonation in a language [syn:
         prosody, inflection]
    2: (prosody) a system of versification [syn: poetic rhythm,
       rhythmic pattern, prosody]
    3: the study of poetic meter and the art of versification [syn:
       prosody, metrics]

Moby Thesaurus II by Grady Ward, 1.0:

36 Moby Thesaurus words for "prosody":
   Stabreim, accent, accentuation, alliterative meter, beat, cadence,
   emphasis, ictus, level of stress, lilt, measure, meter,
   metrical pattern, metrics, movement, number, numbers,
   primary stress, prosodic pattern, prosodics, quantitative meter,
   rhythm, rhythmic pattern, rhythmical stress, scanning, scansion,
   secondary stress, stress, stress accent, stress pattern, swing,
   syllabic meter, tertiary stress, vers libre, versification,
   weak stress