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
Images of birds flutter inside lots of English words and phrases, from “nest egg” and “pecking order,” to proverbs from around the world—including a lovely Spanish saying about how birds sense light just before dawn. Plus...
Unwrap the name of a candy bar, and you just might find a story inside. For instance, one chewy treat found in many a checkout lane is named after a family’s beloved horse. And: 50 years ago in the United States, some Latino elementary...