A noun for “cavern” in the Gnomish Lexicon of the 1910s based on the early root ᴱ√roto (GL/65). In early editions of the Gnomish Lexicon as published, the form was incorrectly given as rodrin, but errata confirmed that word actually meant “cylindrical” and the word for “cavern” was properly rodos (PEE for issue 11), as reported by Christopher Tolkien (LTA2/Rothwarin).
Gnomish
gath
noun. neck
gath
noun. gloom, blight
grûd
noun. cavern
rodos
noun. cavern
An (archaic) word for “gloom, blight” in the Gnomish Lexicon of the 1910s with stem-form gadh-, apparently derived from a variant of ᴱ✶ı̯ādh which was the ancient final element of G. Garioth (GL/37). As such it clearly based on the early root ᴱ√YAÐA with Gnomish form gadh- (QL/105).