top-drain

English

Etymology

From top +‎ drain.

Verb

top-drain (third-person singular simple present top-drains, present participle top-draining, simple past and past participle top-drained)

1. (transitive) To drain the surface of (a field, farm, etc.).
2. To drain water or fluid from the top of a water heater or heating system, rather than from the bottom.