不及物动词
1. 波动；起伏；摇曳
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.
1. increase and decrease in volume or pitch, as if in waves
e.g. The singer's voice undulated
2. move in a wavy pattern or with a rising and falling motion
e.g. The curtains undulated
the waves rolled towards the beach
3. stir up (water) so as to form ripples
Synonym: ripplerufflerifflecockle
4. occur in soft rounded shapes
e.g. The hills rolled past
Synonym: roll