Noun

1. Something with which one is very familiar, or in which one is experienced or skilled.
   • 1946, "New Plays in Manhattan," Time, 11 Nov.,

     Coward is such an old hand at this kind of thing that he makes it seem old hat.

2. Something widely or long practiced, known, or accepted; something conventional.
   • 1987, Elaine Sciolino, "Washington Talk: The Hart Story Grips the Capital," New York Times, 8 May (retrieved 21 June 2008),

     It is old hat for a sex scandal to bring down a politician.

3. Something uninteresting, hackneyed, or passé due to overuse or long-standing familiarity.
   • 2007, Fredrick Kunkle and Paul Duggan, "Straining for a Glimpse of Royalty," Washington Post, 4 May (retrieved 21 June 2008),

     Based on the size of the crowd, perhaps the queen is old hat.