draining

Concise Oxford English Dictionary © 2008 Oxford University Press:
drain/dreɪn/

▶verb

• 1 cause the liquid in (something) to run out, leaving it empty or dry.

  ■ (of liquid) run off or out.

  ■ (of a river) carry off the superfluous water from (an area).

  ■ become dry as liquid runs off.

  ■ drink the entire contents of.

• 2 deprive of strength or vitality.

  ■ cause (a resource) to be used up.

▶noun

• 1 a channel or pipe that carries off rainwater or liquid waste.

  ■ Brit. a grating set in the ground over the opening of a drain.

• 2 a thing that uses up a resource.

  ■ the continuous loss of a resource: the drain of talented staff.

– phrases
go down the drain informal be totally wasted.
laugh like a drain Brit. informal laugh raucously.

– origin OE drēahnian, drēhnian ‘strain liquid’, of Gmc origin; rel. to dry.