#1 undulate v. [ripple, ruffle, riffle, cockle] stir up (water) so as to form ripples. wn
#2 undulate s. having a wavy margin and rippled surface. wn
#3 undulate v. [roll] occur in soft rounded shapes; "The hills rolled past". wn
#4 undulate v. [roll, flap, wave] move in a wavy pattern or with a rising and falling motion; "The curtains undulated"; "the waves rolled towards the beach". wn
#5 undulate v. increase and decrease in volume or pitch, as if in waves; "The singer's voice undulated". wn
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