Definition of "tragacanth"

tragacanth

noun
countable and uncountable, plural tragacanths
1. A polysaccharide gum, extracted from several species of leguminous plants of the genus Astragalus, formerly used medicinally and now as a food additive. Also more fully gum tragacanth.
  Quotations
  Where what I have to note is too much to be included within the narrow limits of a margin, I commit it to a slip of paper, and deposit it between the leaves; taking care to secure it by an imperceptible portion of gum tragacanth paste.
  1844, E.A.Poe, Marginalia
  There would have been many gums and resins in these markets for our lute-maker to bind his wood with: […] gum tragacanth from Aleppo, which would be sold as thin and wrinkled worm-like pieces of shrub.
  2002, Victoria Finlay, Colour, Sceptre, published 2003, page 198