Definitions of undulate:
- verb: increase and decrease in volume or pitch, as if in waves
Example: "The singer's voice undulated"
- verb: occur in soft rounded shapes
- verb: move in a wavy pattern or with a rising and falling motion
Example: "The curtains undulated"
- verb: stir up (water) so as to form ripples
- adjective: having a sinuate margin and rippled surface
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