The Collaborative International Dictionary of English v.0.48:

Astringe \As*tringe"\ ([a^]s*tr[i^]nj"), v. t. [imp. & p. p.
   Astringed (-tr[i^]njd"); p. pr. & vb. n. Astringing
   (-j[i^]ng).] [L. astringere; ad + stringere to draw tight.
   Cf. Astrict, and see Strain, v. t.]
   1. To bind fast; to constrict; to contract; to cause parts to
      draw together; to compress.
      [1913 Webster]

            Which contraction . . . astringeth the moisture of
            the brain and thereby sendeth tears into the eyes.
                                                  --Bacon.
      [1913 Webster]

   2. To bind by moral or legal obligation. --Wolsey.
      [1913 Webster]

WordNet (r) 3.0 (2006):

astringe
    v 1: constrict or bind or draw together; "Lemon juice astringes
         the tissue in the mouth"
    2: become constricted or compressed; "The cold substance
       astringes"