§ Nelig Morn Mel >> Nelig Myrn ’Teeth of Mordor’ (WR:113,122)
§ Naglath Morn (WR:122)
These are epithets for the two towers guarding the entrace to Mordor, earlier Gorgos and Nargos (see 2.58), later Narchost and Carchost ’Towers of the Teeth’ in The Lord of the Rings (LotRVI, ch.1).
Nelig is clearly the plural of N. neleg ’tooth’ (NÉL-EK-). Naglath is obviously formed with the class-plural suffix -ath, so that the basic form can be guessed *nagl, *nagol < *nakla from NAK- ’bite’; compare N. magl, magol ’sword’ from MAK- ’sword’ or ’fight (with sword)’. Mel is probably the beginning of an unfinished word.
The following adjecitve is N./S. morn ’black’ (MOR-, VT45:35; Let:347), interestingly in the singular, although qualifying pl. nelig, naglath. Elsewhere Sindarin and Noldorin adjectives are seen to agree in plural, so that this might be just a slip. In any case Nelig Morn has been immediately changed to Nelig Myrn with pl. myrn, while Naglath Morn was subsequently struck out and not replaced.