Definition of "hygroscopic"

hygroscopic

adjective
comparative more hygroscopic, superlative most hygroscopic
1. (physics, chemistry, botany) Readily taking up and retaining water, especially from the atmosphere.
  Quotations
  The tissues of Ralfsia are dense and the cells are extremely hygroscopic. The plants may become almost crisp dry in the sun, yet remain alive and continue growth with the first splash of the incoming tide.
  1966, E. Yale Dawson, Seashore Plants of Southern Califonria, 3rd printing, Berkley: University of California Press, published 1975, pages 23–24