weather vane

American  

Or weathervane

noun

1. a device, as a rod to which a freely rotating pointer is attached, for indicating the direction of the wind.

---

weather vane British  

noun

1. a vane designed to indicate the direction in which the wind is blowing

---

Etymology

Origin of weather vane

First recorded in 1715–25

Example Sentences

When throngs of visitors move through the show, which started Nov. 8, they’ll create air currents, stirring the mobiles to move in a slow ballet of weather vanes.

From Seattle Times

A museum should not change directions like a weather vane but give us the reassurance that some things are timeless and provide us with the history and progression of art.

From Los Angeles Times

There are weather vanes with more firmly fixed positions.

From Los Angeles Times

Long an integral part of the social calendar, Germany’s roughly 500 Christmas markets have renewed importance as weather vanes of the national mood.

From New York Times

Others say she’s a weather vane, pivoting when it suits her advancement.

From Washington Post