noun

• (nautical) A tankship, a vessel used to transport large quantities of liquid.
  "The channel at Chan-chiang is being dredged to a depth of 50 feet enabling tankers of 70,000 tons to call."
• (automotive, US) A motor truck with a tank to hold bulk liquid (with or without internal baffles).
• (automotive, UK) A fuel tanker, petrol tanker, road tanker.
  "Nor is the government facing a strike by tanker drivers, as was the case in early 1979 during the winter of discontent."
• (aviation, usually military) An aircraft carrying a large supply of jet fuel or avgas for aerial refueling of other aircraft, plus equipment allowing the in-air transfer of fuel.
  "Without the KC-46 tankers orbiting in friendly airspace, our fighters would've run out of fuel long before reaching the combat zone."

verb

• (transitive) To transport (oil, etc.) in a tanker.
• (aviation) To carry more fuel than necessary for a flight, in order to avoid having to refuel at a destination where fuel is more expensive or in short supply.