breaker, 
dumper, ripple, surge, surf, swell 
upsurge, 
groundswell, tendency, trend, movement, surge, flood, surf, swell 
gesture, 
signal, sign 
rash, 
spate, outbreak, epidemic, series, flood, eruption 
current, 
surge, impulse, oscillation, undulation 
curl, 
kink, undulation, ringlet