ETYM Old Eng. bek, AS. becc; akin to Icel. bekkr brook, Old High Germ. pah, German bach.
A beckoning gesture.
A natural stream of water normally smaller than and often tributary to a river.

A small brook.

ETYM Cf. lg. rille a small channel or brook, a furrow, a chamfer, Old Eng. rigol a small brook, French rigole a trench or furrow for water, w. rhill a row, rhigol a little ditch.
A small channel (as one formed by soil erosion).
A very small brook.
Any of several long narrow valleys on the moon's surface.

ETYM Earlier rivolet, Italian rivoletto, a dim. from rivolo, Latin rivulus, dim. of rivus a brook. cf. Rival, Rite.
A small stream; SYN. rill, run, runnel, streamlet.

Rivulet, streamlet

Little brook, rivulet, streamlet