Noun

1. One who puts corks into bottles.
   • 1857, Herman Melville, The Confidence-Man, chapter 30,

     Yes it is, Frank. Don't you see? Laertes is to take the best of care of his friends—his proved friends, on the same principle that a wine-corker takes the best of care of his proved bottles.

2. A person or thing that is exceptional or remarkable.
   • 1889, Mark Twain, A Connecticut Yankee in King Arthur's Court,

     Well, a body is bound to admit that for just a modest little one-line ad., it's a corker.