Noun

• S: (n) ripple, rippling, riffle, wavelet (a small wave on the surface of a liquid)
• S: (n) ripple ((electronics) an oscillation of small amplitude imposed on top of a steady value)

Verb

• S: (v) ripple, ruffle, riffle, cockle, undulate (stir up (water) so as to form ripples)
• S: (v) ripple, babble, guggle, burble, bubble, gurgle (flow in an irregular current with a bubbling noise) "babbling brooks"