Source : Webster's Revised Unabridged Dictionary (1913)

Fleawort \Flea"wort`\, n. (Bot.)
   An herb used in medicine ({Plantago Psyllium}), named from
   the shape of its seeds. --Loudon.

Source : WordNet®

Plantago psyllium
     n : plantain of Mediterranean regions whose seeds swell and
         become gelatinous when moist and are used as a mild
         laxative [syn: {fleawort}, {psyllium}, {Spanish psyllium}]