The Collaborative International Dictionary of English v.0.48:

Scumber \Scum"ber\, v. i. [Cf. Discumber.]
   To void excrement. [Obs. or Prov. Eng.] --Massinger.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Scumber \Scum"ber\, n.
   Dung. [Obs. or Prov. Eng.]
   [1913 Webster]