un·du·late /ˈʌnʤələt, ˈʌndjə, ˈʌndə, ˌlet/
  (a.)波動的,起伏的(vi.)波動,起伏,呈波浪形(vt.)使起伏,使波動
  un·du·late /ˈənʤələt, ˈənd(j)ə, ˌlet/ 形容詞
  (拉undulatus)波狀的,波(浪)形的,波動
  undulate
  波動; 起伏
  Un·du·late a.  Same as Undulated.
  Un·du·late v. t. [imp. & p. p. Undulated p. pr. & vb. n. Undulating.] To cause to move backward and forward, or up and down, in undulations or waves; to cause to vibrate.
     Breath vocalized, that is, vibrated and undulated.   --Holder.
  Un·du·late, v. i. To move in, or have, undulations or waves; to vibrate; to wave; as, undulating air.
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  undulate
       adj : having a sinuate margin and rippled surface
       v 1: stir up (water) so as to form ripples [syn: ripple, ruffle,
             riffle, cockle]
       2: occur in soft rounded shapes; "The hills rolled past" [syn:
          roll]
       3: move in a wavy pattern or with a rising and falling motion;
          "The curtains undulated"; "the waves rolled towards the
          beach" [syn: roll, flap, wave]
       4: increase and decrease in volume or pitch, as if in waves;
          "The singer's voice undulated"