wig-wags
n.— «I’ve had folks tell me that the first thing they saw when I was approaching was the headlights wig-wag: way before my halogen light bar or sealed beam red/blue wig-wags.…Anyone can flash their headlights, but only emergency vehicles have wig-wags ;-).» —“Re: Still More Lights (and wig-wags!)” Usenet: misc.emerg-services Apr. 9, 1991. (source: Double-Tongued Dictionary)
Further reading
In 1971, when a new public library opened in Troy, Michigan, famous authors and artists were invited to write letters to the city’s youngest readers, extolling the many benefits of libraries. One of the loveliest was from E.B. White, author of...
A Vermont listener named Amy is looking for a word to denote a particular kind of light. She has an eye condition that makes her photophobic, which means that ordinary light makes her physically uncomfortable. She wants a word that describes that...