Learn how to say Rivulet correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word rivulet:
1a small stream of water or another liquid:
sweat ran in rivulets down his back
literary a very small river or stream.
2a brownish European moth with white markings, occurring in rough grassland.
Perizoma affinitatum, family Geometridae
late 16th century: alteration of obsolete riveret (from French, literally ‘small river’), perhaps suggested by Italian rivoletto, diminutive of rivolo, based on Latin rivus ‘stream’