rill vs rivulet

rill and rivulet both are nouns.

Word	Noun	Adjective	Verb	Adverb
rill	Yes	No	No	No
rivulet	Yes	No	No	No

As nouns, rill and rivulet are synonyms defined as:

Other synonyms of rill include run, runnel, streamlet.

rill (noun)	rivulet (noun)
a small stream	a small stream
a small channel (as one formed by soil erosion)