dim

adjective (dimmer, dimmest)

• 1(of a light, colour, or illuminated object) not shining brightly or clearly:the dim glow of the fire
• (of an object or shape) made difficult to see by darkness, shade, or distance:a dim figure in the dark kitchen
• (of a room or other space) made difficult to see in by darkness:long dim corridors
• (of the eyes) unable to see clearly: his eyes became dim
• (of a sound) indistinct or muffled:the dim drone of their voices
• not clearly recalled or formulated in the mind:dim memories the matter was in the dim and distant past

• 2(of a situation) not giving cause for hope or optimism:their prospects for the future looked fairly dim

• 3 informal stupid or slow to understand: you’re just incredibly dim

verb (dims, dimming, dimmed)

• make or become less bright or distinct: [with object]:a smoky inferno that dimmed the sun [no object]:the lights dimmed and the curtains parted
• [with object] lower the beam of (a vehicle’s headlights) to avoid dazzling oncoming drivers: (as adjective dimmed)the car moved slowly, its headlights dimmed
• make or become less intense: [with object]:the difficulty in sleeping couldn’t dim her happiness
• make or become less able to see clearly: [no object]:his eyes dimmed