Webster's Revised Unabridged Dictionary · 1913

Beetle-browed

Beetle-browed ({not transcribed})

[Old English bitelbrowed; compare Old English bitel, adj., sharp, projecting, n., a beetle. See Beetle an insect.]

Having prominent, overhanging brows; hence, lowering or sullen.

The earlier meaning was, “Having bushy or overhanging eyebrows.”