Rill vs Brill - What's the difference?

As a noun rill

is furrow, groove.

(wikipedia rill) (en noun)

A very small brook; a streamlet.

* 1797 , :

So twice five miles of fertile ground

With walls and towers were girdled round:

And there were gardens bright with sinuous rills ,

Where blossomed many an incense-bearing tree;

And here were forests ancient as the hills,

Enfolding sunny spots of greenery.

(planetology)

(en verb)

To run a small stream.

(Prior)

Possibly from (etyl)

(en noun)

A type of flatfish, .

Abbreviation of (brilliant).

(en adjective)

(UK, slang) Wonderful, clever, amusing. Denotes approval of the noun it is applied to, comparable to "cool".