An Ilkorin noun for “torrent” (Ety/STAL), apparently a combination of the adjective thall “falling steeply” and the suffix -os.

Conceptual Development: Since the river-name Thalos survived in Tolkien’s later writings (S/123), thalos “torrent” may have become Sindarin, but compare [N.] thórod “torrent” (Ety/THOR).