drain in WordNet English dictionary

1. make weak
   "Life in the camp drained him"
   enfeeble  debilitate  drain 
   
2. empty of liquid; drain the liquid from
   "We drained the oil tank"
   drain 
   
3. deplete of resources
   "The exercise class drains me of energy"
   drain 
   
4. flow off gradually
   "The rain water drains into this big vat"
   drain  run out 
   

1. emptying something accomplished by allowing liquid to run out of it
   drain  drainage 
   
2. a gradual depletion of energy or resources
   "a drain on resources"; "a drain of young talent by emigration"
   drain 
   
3. a pipe through which liquid is carried away
   drain  drainpipe  waste pipe 
   
4. tube inserted into a body cavity (as during surgery) to remove unwanted material
   drain