Half-light is that dull, grey, in-between light when day is slipping into night, or night is just beginning to lift — not bright, not black. You can still see shapes, but colours go quiet and faces go soft. It is the light of dusk, of a room with the curtains half drawn, of a street before the lamps really take over. Writers like the word because it feels still and a little secret; you will see it in stories more than on a weather report. It is not a kind of lamp, and it is not a scientific name. It is simply light that is only half there. People also use it for any dim indoor glow that is not full daylight.