Channels or pipes that carry away unwanted liquid, or the act of removing liquid from something. Can also mean to exhaust or deplete resources or energy.
From Old English drēahnian meaning 'to strain out, filter.' Related to dry and possibly to Greek tragein 'to gnaw.' The sense evolved from filtering liquids to removing them entirely, and by extension to depleting anything valuable.
The metaphorical power of 'drain' in phrases like 'brain drain' or 'draining your energy' shows how we conceptualize abstract losses through the concrete image of liquid flowing away. Ancient drainage systems were so crucial to civilization that many cities' locations were determined by their ability to manage water flow.
Complete word intelligence in one call. Free tier — 50 lookups/day.