The Collaborative International Dictionary of English v.0.48:

Popple \Pop"ple\, v. i. [Cf. Pop.]
   To move quickly up and down; to bob up and down, as a cork on
   rough water; also, to bubble. --Cotton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Popple \Pop"ple\, n.
   1. The poplar. [Prov. Eng. & Local, U. S.]
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   2. Tares. [Obs.] "To sow popple among wheat." --Bale.
      [1913 Webster]