sidelight

Noun

sidelight (plural sidelights)

1. A light found at the side of something; especially of a vehicle.
   • If it starts getting misty, put your sidelights on.
   • After dark the train is a lighted snake, as, even when the passengers' lights are out, each carriage has a side-light in the middle just under the eaves.1950 April, Timothy H. Cobb, “The Kenya-Uganda Railway”, in Railway Magazine, page 263
   1. (broadly) (nautical) Red and green navigation lights indicating each side of a ship for collision avoidance; red on the port (left) and green on the starboard.
2. A window found at one or both sides of a door.
3. A piece of incidental information that helps one understand a subject.
   • A book of this type is necessarily mainly factual, but it is diversified by many incidents and sidelights which help to give life to a story now accorded its due place in railway history.1957 December, “Railway Literature: Southern Electric. By G. T. Moody”, in Railway Magazine, page 892
   • He is well up to form when dealing with passenger stock, notably Victorian and Edwardian and on this and on East Coast motive power he throws many sidelights.1962 October, “New Reading on Railways: The Flying Scotsman 1862-1962. By C. Hamilton Ellis. Allen & Unwin. 6s.”, in Modern Railways, unnumbered page