Pronunciation: (yar'ō),[key] —n. 1. a composite plant, Achillea millefolium, of Eurasia, having fernlike leaves and flat-topped clusters of whitish flowers, naturalized in North America.
2. any of various other plants of the genus Achillea, some having yellow flowers.
Pronunciation: (yar'ō),[key] —n. a river in SE Scotland, flowing into the Tweed. 14 mi. (23 km) long.