Nouns

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

Verbs

(v)ripple, ruffle, riffle, cockle, undulatestir up (water) so as to form ripples
(v)ripple, babble, guggle, burble, bubble, gurgleflow in an irregular current with a bubbling noise“babbling brooks”