ripple

(noun) a small wave on the surface of a liquid. Synonyms: rippling, riffle, wavelet.

(noun) (electronics) an oscillation of small amplitude imposed on top of a steady value.

(verb) stir up (water) so as to form ripples. Synonyms: ruffle, riffle, cockle, undulate.

(verb) flow in an irregular current with a bubbling noise. Synonyms: babble, guggle, burble, bubble, gurgle. Examples: "Babbling brooks."