The Collaborative International Dictionary of English v.0.48:

Palaestra \Pa*l[ae]s"tra\, n.
   See Palestra.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Palestra \Pa*les"tra\, n.; pl. L. Palestr[ae], E. Palestras.
   [NL., fr. L. palaestra, Gr. ?, fr. ? to wrestle.] [Written
   also pal[ae]stra.] (Antiq.)
   (a) A wrestling school; hence, a gymnasium, or place for
       athletic exercise in general.
   (b) A wrestling; the exercise of wrestling.
       [1913 Webster] Palestric
       Palestrian

WordNet (r) 3.0 (2006):

palaestra
    n 1: a public place in ancient Greece or Rome devoted to the
         training of wrestlers and other athletes [syn: palestra,
         palaestra]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "palaestra":
   Rugby, acrobatics, agonistics, agora, amphitheater, arena,
   association football, athletic field, athletics, auditorium,
   background, bathing, bear garden, bowl, boxing ring, bull ring,
   campus, canvas, circus, cockpit, coliseum, colosseum, course,
   fencing school, field, floor, forum, ground, gym, gymnasium,
   gymnastics, hall, hippodrome, lists, locale, marketplace, mat,
   milieu, natation, open forum, parade ground, pit, place, platform,
   precinct, prize ring, public square, purlieu, range, ring, rugger,
   scene, scene of action, scenery, setting, site, soccer, sphere,
   sports, squared circle, stadium, stage, stage set, stage setting,
   swimming, terrain, theater, tilting ground, tiltyard, track,
   track and field, tumbling, walk, wrestling ring,
   wrestling school