Source : Webster's Revised Unabridged Dictionary (1913)

Glower \Glow"er\, v. i. [imp. & p. p. {Glowered}; p. pr. & vb.
   n. {Glowering}.] [Cf. {Gloar}.]
   to look intently; to stare angrily or with a scowl.
   --Thackeray.

Source : WordNet®

glower
     n : an angry stare [syn: {glare}]
     v 1: look at with a fixed gaze; "The girl glared at the man who
          tried to make a pass at her" [syn: {glare}]
     2: look angry or sullen, wrinkle one's forehead, as if to
        signal disapproval [syn: {frown}, {lour}, {lower}]