aglæca

Etymology
From. A difficult and much-debated word. Possibly in origin a compound from the root of (Bosworth 1882), but this is disputed.

Found mostly in poetry, and there mostly of monsters and devils, but once of Beowulf and once of Sigemund. The sole attestation in prose is also a unique relational adjectival use, in Byrhtferth's Enchiridion, where it refers to the scholar Bede as se æglæca lareow, making clear that the word is not inherently pejorative but carries a meaning of "awe-inspiring, formidable".

Noun

 * 1)  an awesome or formidable opponent, ferocious fighter
 * 2) a miserable being, wretch, monster