WordNet (r) 3.0 (2006):

earthbound
    adj 1: confined to the earth
    2: lacking wit or imagination; "a pedestrian movie plot" [syn:
       pedestrian, prosaic, prosy, earthbound]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "earthbound":
   arid, barren, dry, dull, earth, earthly, fluvioterrestrial,
   geophilous, infecund, infertile, literal, mundane, prosaic,
   prosing, prosy, staid, stolid, stuffy, subastral, sublunar,
   tellurian, telluric, terraqueous, terrene, terrestrial, unfanciful,
   unideal, unimaginative, uninspired, uninventive, unoriginal,
   unpoetic, unromantic, unromanticized