Doriathrin
brithon
adjective. pebbly
brithon
place name. Pebbly
brithombar
place name. *Brithon-home
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
An Ilkorin adjective meaning “pebbly” used for the river name Brithon (Ety/BIRÍT). It seems to be a combination of brith “broken stones, gravel” and an adjective suffix -on.