Coot
Coot (kot) , noun
[Compare Dutch koet, Welsh cwtair; cwta short, bodtailed + iar hen; compare cwtau to dock. Compare Cut.]
1.
(a) (Zoology) A wading bird with lobate toes, of the genus Fulica. The common European or bald coot is Fulica atra (see under bald); the American is Fulica Americana
(b)
(Zoology) The surf duck or scoter. In the United States all the species of (Odemia are called coots. See Scoter.
As simple as a coot.
2.
A stupid fellow; a simpleton; as, a silly coot. [Colloquial]