wig-wag n. a rapidly alternating or strobing warning light. Also attributive. Editorial Note: Often plural, since the lights are rarely used singly. Semaphore flags have long been called “wig-wags” in the Navy, Marines, and other military and paramilitary organizations. (source: Double-Tongued Dictionary)
Further reading
The owner of a Berlin, Maryland, produce stand wants to know: When a customer is buying four ears of corn, should they say I have four corn or I have four ears of corn? Corn is a mass noun that can also be counted as a plural, just as we might say I...
When there’s no evening meal planned at home, what do you call that scramble to cobble together your own dinner? Some people apply acronyms like YOYO — “you’re on your own” — or CORN, for “Clean Out your Refrigerator...