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.
masculine name. Biting-Storm
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).
Word Gloss anc “jaw, row of teeth” alagos “storm (of wind)”