{f} cause to move in waves; form waves; move as a wave; possess a wave-like shape; display a wavy appearance
Something that undulates has gentle curves or slopes, or moves gently and slowly up and down or from side to side in an attractive manner. As we travel south, the countryside begins to undulate as the rolling hills sweep down to the riverbanks His body slowly undulated in time to the music. + undulating un·du·lat·ing gently undulating hills. to move or be shaped like waves that are rising and falling
increase and decrease in volume or pitch, as if in waves; "The singer's voice undulated" having a sinuate margin and rippled surface
To have a wavy form or surface; bend with successive curves in alternate directions, specifically in an up-down direction (not in an in-out direction)