ripple
/ˈrɪp.əl/noun
CEFR B1
Definition
A small wave or series of small waves on the surface of water.
Think of dropping a single stone into a still pond: the small circles that spread outward are ripples. The word is also used for something that spreads gradually and gently through a group of people, like a ripple of laughter moving through a crowd.
Synonyms
wave
wavelet
undulation