What does the word oak mean?

Usage examples for oak

  1. Never sport your oak, old boy; it's a bad habit. – Tom Brown at Oxford by Thomas Hughes
  2. Don't you want to see the Charter Oak? – Dawson Black: Retail Merchant by Harold Whitehead
  3. Five people sat down to breakfast under the great oak- tree, and it was a lively meal. – The Associate Hermits by Frank R. Stockton