rill Definition

rill
noun

1. A small stream or brook.
2. A small trench or furrow.
3. astron.
See rille.
4. phonetics.
A fricative produced by forcing air out of a small gap formed between the tongue and the roof of the mouth.

Derivative: rilled
adj

Etymology: 16c.

---

rille
rill
noun

1. astron.
A long narrow trench or valley on the moon, formed by volcanic activity.

Etymology: 19c: German, meaning ‘a groove'.