What is a dim or intermittent flicker or flash of light called?

The phenomenon described as a dim or intermittent flicker or flash of light is accurately referred to as a glimmer. This term specifically captures the transient and subtle nature of the light, suggesting a brief or soft shine that may come and go.

In contrast, "glisten" typically describes a continuous shine that reflects light, often associated with moisture or something that sparkles rather than flashing intermittently. "Gorge" is unrelated to light; it refers to a deep ravine or a narrow valley, making it irrelevant to the context of flickering light. "Glow" implies a steady, consistent illumination rather than a flickering effect, which distinguishes it from the concept of a glimmer. Thus, glimmer is the correct term to describe a fleeting flash of light, aligning precisely with the question's definition.