ascend
billow
billowy
blob
bottom
bounce
decline
descend
downhill
fall
flap
flicker
flow
flowing
fluctuate
fluctuation
flutter
horizontal
incline
jiggle
landscape
mountain
natural
nature
oscillate
oscillation
peak
pitch
ripple
rippley
ripply
rise
shift
silhouette
smooth
surge
sway
swing
tide
top
undulate
undulating
uprise
wave
waveform
waving
wavy
wobble
writhe