An element of the name Q. i Tumbo Tarmacorto for the valley of Gondolin, meaning “High Mountain Circle” (NM/351). A possible etymology is that the first element is Q. tarma, normally “pillar” but used of a high mountain in Q. Meneltarma, and the second element is some derivative of √KOR “round”, perhaps an otherwise unattested word *Q. corto “circle”. This etymology was suggested to me on a Discord chat in 2021-11-09 by Röandil.