The Collaborative International Dictionary of English v.0.48:

Clamber \Clam"ber\, v. i. [imp. & p. p. Clambered; p. pr. &
   vb. n. Clambering.] [OE clambren, clameren, to heap
   together, climb; akin to Icel. klambra to clamp, G. klammern.
   Cf. Clamp, Climb.]
   To climb with difficulty, or with hands and feet; -- also
   used figuratively.
   [1913 Webster]

         The narrow street that clambered toward the mill.
                                                  --Tennyson.
   [1913 Webster]