The Collaborative International Dictionary of English v.0.48:

Jongleur \Jon"gleur\, Jongler \Jon"gler\, n. [F. jongleur. See
   Juggler.]
   [1913 Webster]
   1. In the Middle Ages, a court attendant or other person who,
      for hire, recited or sang verses, usually of his own
      composition. See Troubadour.
      [1913 Webster]

            Vivacity and picturesquenees of the jongleur's
            verse.                                --J R. Green.
      [1913 Webster]

   2. A juggler; a conjuror. See Juggler. --Milton. Jonquil

WordNet (r) 3.0 (2006):

jongleur
    n 1: a singer of folk songs [syn: folk singer, jongleur,
         minstrel, poet-singer, troubadour]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "jongleur":
   Meistersinger, Parnassian, arch-poet, ballad maker, ballad singer,
   balladeer, balladmonger, bard, beat poet, bucoliast, elegist,
   epic poet, fili, folk singer, folk-rock singer, gleeman, idyllist,
   imagist, laureate, librettist, major poet, maker, minnesinger,
   minor poet, minstrel, modernist, occasional poet, odist,
   pastoral poet, pastoralist, poet, poet laureate, poetress,
   rhapsode, rhapsodist, satirist, scop, serenader, skald, sonneteer,
   street singer, strolling minstrel, symbolist, troubadour, trouveur,
   trovatore, vers libriste, vers-librist, wait, wandering minstrel