The Collaborative International Dictionary of English v.0.48:

Suint \Su"int\ (s[=u]"[i^]nt), n. [F.] (Chem.)
   A peculiar substance obtained from the wool of sheep,
   consisting largely of potash mixed with fatty and earthy
   matters. It is used as a source of potash and also for the
   manufacture of gas.
   [1913 Webster]