The Quenya form of S. Angband (MR/350), a compound of anga “iron” and mando “prison”.
Conceptual Development: This name first appeared as ᴱQ. Eremandu and (plural) Angamandi “Hells of Iron”, the first of these using another word for “iron”: ᴱQ. ere(n) (QL/36, LT1/77). At this early stage, the second element was ᴱQ. mandu “hell” (QL/58). In The Etymologies from the 1930s, it was replaced by the singular form ᴹQ. Angamanda “Iron Prison” (Ety/MBAD), eventually altered to Angamando in Silmarillion revisions from the 1950s-60s (MR/350).
Angamando place-name "Iron-gaol", Sindarin Angband(MR:350). The Etymologies gives Angamanda "Angband, Hell", lit. "Iron-prison" (MBAD, VT45:33). In deleted material in the Etymologies, the Quenya name of Angband was Angavanda (VT45:6); cf. vanda #2. Older "Qenya" has Angamandu "Hells of Iron" (or pl. Angamandi) (LT1:249).