The Collaborative International Dictionary of English v.0.48:

Roulade \Rou`lade"\, n. [F.] (Mus.)
   A smoothly running passage of short notes (as semiquavers, or
   sixteenths) uniformly grouped, sung upon one long syllable,
   as in Handel's oratorios.
   [1913 Webster]

WordNet (r) 3.0 (2006):

roulade
    n 1: a dish consisting of a slice of meat that is rolled around
         a filling and cooked
    2: (music) an elaborate run of several notes sung to one
       syllable