Source : Webster's Revised Unabridged Dictionary (1913)

Frostwort \Frost`wort"\, n. (Bot.)
   Same as {Frostweed}.

Source : WordNet®

frostwort
     n : perennial of the eastern United States having early solitary
         yellow flowers followed by late petalless flowers;
         so-called because ice crystals form on it during first
         frosts [syn: {frostweed}, {frost-weed}, {Helianthemum
         canadense}, {Crocanthemum canadensei}]