undulate - Dictionary definition and meaning for word undulate
I have been able to remember this as 'Modulation'. change in a wave like manner.
unda's (eggs) staced next to each other will look like a wave
und= wave, flow; abundant :: overflow, plentiful; redundant:: too much flows, excess; inundate:: in the flow,flooded ; undulate:: move like waves. Example::undulating hills
undulate sounds like fluctuate
Like the oscillations of a pendulum