The Collaborative International Dictionary of English v.0.48:

Gnomic \Gnom"ic\, Gnomical \Gnom"ic*al\, a. [Gr. ?, fr. ?: cf.
   F. gnomique. See Gnome maxim.]
   Sententious; uttering or containing maxims, or striking
   detached thoughts; aphoristic.
   [1913 Webster]

         A city long famous as the seat of elegiac and gnomic
         poetry.                                  --G. R. Lewes.
   [1913 Webster]

   Gnomic Poets, Greek poets, as Theognis and Solon, of the
      sixth century B. C., whose writings consist of short
      sententious precepts and reflections.
      [1913 Webster]

WordNet (r) 3.0 (2006):

gnomic
    adj 1: relating to or containing gnomes; "gnomic verse"

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "gnomic":
   Spartan, abbreviated, abridged, aphoristic, aposiopestic,
   axiomatic, brief, brusque, clipped, close, compact, compendious,
   compressed, concise, condensed, contracted, crisp, curt, cut,
   docked, elliptic, epigrammatic, formulaic, formulistic, laconic,
   pithy, platitudinous, pointed, proverbial, pruned, pungent,
   reserved, sententious, short, short and sweet, shortened, succinct,
   summary, synopsized, taciturn, terse, tight, to the point,
   truncated