hat 
(hăt)
(hăt)n.
1. A covering for the head, especially one with a shaped crown and brim.
2.
a. A head covering of distinctive color and shape worn as a symbol of office.
b. The office symbolized by the wearing of such a head covering.
3. A role or office symbolized by or as if by the wearing of different hats: wears two hats—one as parent and one as corporate executive.
tr.v. hat·ted, hat·ting, hats
Idioms: To supply or cover with a hat.
at the drop of a hat
At the slightest pretext or provocation.
hat in hand
In a humble manner; humbly.
take (one's) hat off to
To respect, admire, or congratulate.
talk through (one's) hat
1. To talk nonsense.
2. To bluff.
throw/toss (one's) hat into the ring
To enter a political race as a candidate for office.
under (one's) hat
As a secret or in confidence: Keep this information under your hat.
[Middle English, from Old English hæt, hætt.]