The hill upon which Dol Guldur was built, translated “Naked Hill” (UT/280). It is a combination of amon “hill” and lanc “naked”.
Sindarin
Amon Lanc
noun. naked hill
amon lanc
place name. Naked Hill
Elements
Word Gloss amon “hill, mountain with steep sides; lump, clump, mass, hill, (isolated) mountain; lump, clump, mass; [G.] steep slope” lanc “naked”
Amon Lanc
Naked Hill
amon (“hill, steep-sided mount”), lanc (“naked”)