Gath Forthnír doorway

If you turn around and look at the doorframe of the entrance into the cavern of Gath Forthnír in eastern Angmar, you can see inscription written in Tengwar, probably in Sindarin tehta-mode.

Composed of the Tengwar rómen, silme + e or u tehta, and tinco, the word appears to be either rest or rust.

rest, Sindarin for cleft, ravine, cut

rust, Sindarin for copper