The Collaborative International Dictionary of English v.0.48:

Quaking \Quak"ing\,
   a. & n. from Quake, v.
   [1913 Webster]

   Quaking aspen (Bot.), an American species of poplar
      (Populus tremuloides), the leaves of which tremble in
      the lightest breeze. It much resembles the European aspen.
      See Aspen.

   Quaking bog, a bog of forming peat so saturated with water
      that it shakes when trodden upon.

   Quaking grass. (Bot.)
   (a) One of several grasses of the genus Briza, having
       slender-stalked and pendulous ovate spikelets, which
       quake and rattle in the wind. Briza maxima is the large
       quaking grass; Briza media and Briza minor are the
       smaller kinds.
   (b) Rattlesnake grass (Glyceria Canadensis).
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Quake \Quake\, v. i. [imp. & p. p. Quaked; p. pr. & vb. n.
   Quaking.] [AS. cwacian; cf. G. quackeln. Cf. Quagmire.]
   1. To be agitated with quick, short motions continually
      repeated; to shake with fear, cold, etc.; to shudder; to
      tremble. "Quaking for dread." --Chaucer.
      [1913 Webster]

            She stood quaking like the partridge on which the
            hawk is ready to seize.               --Sir P.
                                                  Sidney.
      [1913 Webster]

   2. To shake, vibrate, or quiver, either from not being solid,
      as soft, wet land, or from violent convulsion of any kind;
      as, the earth quakes; the mountains quake. " Over quaking
      bogs." --Macaulay.
      [1913 Webster]