- The definition of a rivulet is a very small stream.
A little stream of water in your back yard that is about 2 feet deep and 2 feet wide and that runs over some rocks down to the lake at the base of a hill is an example of a rivulet.
rivulet definition by Webster's New World
Origin: earlier rivolet ; from Italian rivoletto, diminutive of rivolo, diminutive of rivo, stream ; from Classical Latin rivus, brook, stream: see rival
rivulet definition by American Heritage Dictionary
Origin: Possibly from Italian rivoletto, diminutive of rivolo, small stream, from Latin rīvulus, diminutive of rīvus, stream; see rei- in Indo-European roots.