Any ship which does not have a fixed schedule or published ports of call.
I was so happy on board that ship, I could not have believed it possible. We had the beastliest weather, and many discomforts; but the mere fact of its being a tramp-ship gave us many comforts; we could cut about with the men and officers, stay in the wheel-house, discuss all manner of things, and really be a little at sea.
Then I think I conceive of other worlds and vast structures that pass us by, within a few miles, without the slightest desire to communicate, quite as tramp vessels pass many islands without particularizing one from another.