Glowering is a type of facial expression that conveys anger, frustration, or disapproval. It is similar to glares, stares, and scowls, but is more intense. Glaring is when someone looks at another person with an angry or hostile expression. Staring is when someone looks at another person for a long period of time without blinking. Scowling is when someone frowns deeply in a threatening manner. All three of these expressions are forms of glowering.