blur vs twilight

To make indistinct or hazy, to obscure or dim. 

To cause imperfection of vision in; to dim; to darken. 

To become indistinct. 

To transfer the input focus away from. 

To smear, stain or smudge. 

In a state of doubt or confusion. 

To illuminate faintly. 

Any faint light through which something is seen; an in-between or fading condition. 

The soft light in the sky seen before the rising and (especially) after the setting of the sun, occasioned by the illumination of the earth’s atmosphere by the direct rays of the sun and their reflection on the earth. 

The time when this light is visible; the period between daylight and darkness. 

The time when the sun is less than 18° below the horizon.