1) Architectural element 2) Babbling brook 3) Brook 4) Brooklet 5) Creek 6) Freshet 7) It runs through April leas 8) Junior brook 9) Junior river 10) Little brook 11) Little stream 12) Little streamlet 13) Lunar crevice 14) Lunar trench 15) Lunar valley 16) Mini stream 17) Modest brook 18) Moon site 1) Brook 2) Rivulet 3) Runnel 4) Stream 5) Streamlet 
In hillslope geomorphology, a rill is a shallow channel (no more than a few tens of centimetres deep) cut into soil by the erosive action of flowing water. Similar but smaller incised channels are known as microrills; larger incised channels are known as gullies. Artificial rills are channels constructed to carry a water supply from a distant wate...
• (n.) A very small brook; a streamlet. • (v. i.) To run a small stream. • (n.) See Rille.
A steep-sided small channel resulting from accelerated erosion; the most common form of erosion.
Rill intransitive verb To run a small stream. [ R.] Prior. Rill (rĭl) noun [ Confer LG. rille a small channel or brook, a furrow, a chamfer, Middle English rigol a small brook, French rigole a trench or furrow for water, W. rhill a row, rhigol a little ditch. √11.] 1. A very small brook; a streamlet. 
A very small stream.
An irrigation term for a small stream of water turned onto the surface of a field. (The term also has a non-agricultural use.)
A very small steep sided channel carrying water. This landscape feature is intermittent and forms for only a short period of time after a rainfall.
[n] - a small channel (as one formed by soil erosion)
A small channel eroded into the soil by surface runoff; can be easily smoothed out or obliterated by normal tillage.