rarefied

rarefied
    adj 1: having low density; "rare gasses"; "lightheaded from the
           rarefied mountain air" [syn: {rare}, {rarefied},
           {rarified}]
    2: of high moral or intellectual value; elevated in nature or
       style; "an exalted ideal"; "argue in terms of high-flown
       ideals"- Oliver Franks; "a noble and lofty concept"; "a grand
       purpose" [syn: {exalted}, {elevated}, {sublime}, {grand},
       {high-flown}, {high-minded}, {lofty}, {rarefied}, {rarified},
       {idealistic}, {noble-minded}]
    

Rarefy \Rar"e*fy\ (r[a^]r"[-e]*f[imac]; 277), v. t. [imp. & p.
   p. {Rarefied} (r[a^]r"[-e]*f[imac]d); p. pr. & vb. n.
   {Rarefying} (r[a^]r"[-e]*f[imac]`[i^]ng).] [F. rar['e]fier;
   L. rarus rare + -ficare (in comp.) to make; cf. L.
   rarefacere. See {-fy}.]
   To make rare, thin, porous, or less dense; to expand or
   enlarge without adding any new portion of matter to; --
   opposed to condense.
   [1913 Webster]
    

94 Moby Thesaurus words for "rarefied":
      adulterated, air-built, airy, attenuate, attenuated, boyish,
      chimerical, clannish, cliquish, cloud-built, cut, dainty, delicate,
      diaphanous, dilute, diluted, dreamlike, elevated, esoteric,
      ethereal, exalted, exclusive, fanciful, fatuitous, fatuous, fine,
      fine-drawn, finespun, flimsy, frail, gaseous, gauzy, girlish,
      gossamer, gossamery, gracile, high, illusory, imaginary,
      insubstantial, lacy, lean, light, lofty, misty, noble, papery,
      phantomlike, private, rare, reduced, scant, scanty, select,
      shadowy, slender, slenderish, slight, slight-made, slim, slimmish,
      slinky, small, sparse, spirituous, sublime, subtile, subtle,
      svelte, sylphlike, tenuous, thin, thin-bodied, thin-set, thin-spun,
      thinned, thinned-out, thinnish, threadlike, uncompact,
      uncompressed, unreal, unsubstantial, vague, vaporous, wasp-waisted,
      watered, watered-down, watery, weak, willowy, windy, wiredrawn,
      wispy