thanc is a Noldorin word meaning "forked".
Since thanc appears in the name Orthanc, Didier Willis has suggested that thanc (retaining the same meaning) would be valid Sindarin.
The word derives from Old Noldorin sthanka, from root STAK.
- ↑ 1.0 1.1 1.2 J.R.R. Tolkien, Christopher Tolkien (ed.), The Lost Road and Other Writings, "Part Three: The Etymologies", p. 388
- ↑ Didier Willis, Hiswelókë's Sindarin Dictionary at Jrrvf.com (accessed 19 June 2011)
- ↑ Compound Sindarin Names in Middle-earth at Tolkiendil.com (accessed 27 June 2011)