Noldorin
ungol
noun. spider
ungol
noun. spider
kirith ungol
place name. Spider Glen
terch ungol
place name. Spider’s Hole, Spider’s Lair
thlingril
noun. spider
dúath
noun. darkness, shadow
dúath
noun. nightshade
dúwath
noun. darkness, shadow
dúwath
noun. nightshade
môr
noun. darkness, dark, night
thling
noun. spider, spider's web, cobweb
thlingril
noun. spider
A noun appearing as N. thlingril “spider” in The Etymologies, probably a feminine form of N. thling “spider, spider’s web, cobweb” (Ety/SLIG). Christopher Tolkien said the r was uncertain.
Neo-Sindarin: Since initial sl- became lh- in Sindarin, most Neo-Sindarin writers adapt this word as ᴺS. lhingril, as suggested in HSD (HSD). This word is somewhat questionable, since in later writings √ungu- was the basis for spider words (PE22/160). I think ᴹ√SLIG may be reinterpreted as having to do with threads, and as such I think ᴺS. lhingril can be retained as originally meaning “(female) web spinner”. However, I recommend later S. ungol as the more common Sindarin word for “spider”.