tragacanth

noun

1. a white or reddish, tasteless and odorless gum, used in pharmacy, calico printing, etc.
2. any of various, esp. Asiatic, plants (genus Astragalus) of the pea family, yielding this gum

Origin: Fr tragacanthe < L tragacantha < Gr tragakantha < tragos, goat (see tragedy) + akantha, thorn (see acantho-)