drain ‧ age /ˈdreɪnɪdʒ/ BrE AmE noun [uncountable]
the process or system by which water or waste liquid flows away:
A handful of pebbles in the bottom of a flowerpot will help drainage.
a plan to improve the town’s drainage system
drain ‧ age /ˈdreɪnɪdʒ/ BrE AmE noun [uncountable]
the process or system by which water or waste liquid flows away:
A handful of pebbles in the bottom of a flowerpot will help drainage.
a plan to improve the town’s drainage system
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012