A Doriathrin noun for “cave”, also appearing as roth, derived from primitive ᴹ✶rǭda or ᴹ✶roda (Ety/ROD, EtyAC/ROD). The [[ilk|[d] spirantilized to [ð] (“dh”)]] as usual, then after the final vowel was lost the [[ilk|final [ð] became [θ]]] as suggested by Helge Fauskanger (AL-Doriathrin/roth). The original sound [ð] is preserved in the plural rodhin.
Doriathrin
rond
noun. domed roof
rôth
noun. cave
A noun meaning “domed roof” derived from a nasal-infixed form of the root ᴹ√ROD “roof, cave” (Ety/ROD).