Coot (noun)

1. A waterbird of the rail family, having mainly black plumage, short wings, and a short tail.
2. A foolish or eccentric old person.
3. A bird species with a black head, white bill and white shield behind the eye, have lobed toes and are found in freshwater wetlands worldwide.

Origin:

The word "coot" is of uncertain origin, but it is first recorded in the 15th century.

Examples:

1. The coot swam in the pond.
2. The old man was called a coot because of his eccentric behavior.
3. The coot is a common bird species in freshwater wetlands.
4. The coot's bill is white with a dark band at the tip.
5. The coot has lobed toes, which help it to walk on floating vegetation.