What is the meaning of drain?

noun

• Emptying something accomplished by allowing liquid to run out of it.
  • synonyms: drainage
• Tube inserted into a body cavity (as during surgery) to remove unwanted material.
• A pipe through which liquid is carried away.
  • synonyms: drainpipe, waste pipe
• A gradual depletion of energy or resources.
  • usage: "a drain on resources"; "a drain of young talent by emigration"

verb

• Flow off gradually.
  • usage: "The rain water drains into this big vat"
  • synonyms: run out
• Deplete of resources.
  • usage: "The exercise class drains me of energy"
• Empty of liquid; drain the liquid from.
  • usage: "We drained the oil tank"
• Make weak.
  • usage: "Life in the camp drained him"
  • synonyms: enfeeble, debilitate