one of a series of ridges that moves across the surface of a liquid (especially across a large body of water)

a movement like that of a sudden occurrence or increase in a specified phenomenon

(physics) a movement up and down or back and forth

something that rises rapidly

the act of signaling by a movement of the hand

a hairdo that creates undulations in the hair

an undulating curve

a persistent and widespread unusual weather condition (especially of unusual temperatures)