- a composite plant, Achillea millefolium, of Eurasia, having fernlike leaves and flat-topped clusters of whitish flowers, naturalized in North America.
- any of various other plants of the genus Achillea, some having yellow flowers.
- a river in SE Scotland, flowing into the Tweed. 14 miles (23 km) long.
- any of several plants of the genus Achillea, esp A. millefolium, of Eurasia, having finely dissected leaves and flat clusters of white flower heads: family Asteraceae (composites)