Sindarin 

Ancalagon

noun. jaws-rushing

anc (“jaw, row of teeth”) + alag (“rushing, impetuous”) + #on (#male ending); LRW:417 translates it as “Biting Storm”, the final element probably alagos “storm”, with a change of the last consonant.

Sindarin [Tolkiendil] Group: Tolkiendil Compound Sindarin Names. Published by

ancalagon

masculine name. Biting-Storm

Greatest of the dragons, slain by Eärendil (S/252). His name is translated “Biting-Storm”, possibly a combination of anc “jaw” and a variant of [N.] alagos “storm of wind”.

Conceptual Development: This name first appeared in Silmarillion drafts from the 1930s (SM/160). The name is translated in The Etymologies from the 1930s (Ety/NAK) but not in later writings. The decomposition above is derived from the entries in The Etymologies (Ety/ÁLAK, ÁNAK, NAK).

Elements

WordGloss
anc“jaw, row of teeth”
alagos“storm (of wind)”
Sindarin [LotRI/Ancalagon; PMI/Ancalagon; SA/alqua; SA/anca; SI/Ancalagon; WJI/Ancalagon] Group: Eldamo. Published by