The story
Apparently named after a former public house, a pub name that crops up elsewhere, but there is some resemblance to the frame of a harp in the shape of the reservoir. This is the popular name, the official name (Brent Reservoir) probably comes from the River Brent, which is both inlet and outlet.
First known use, by meaning
- from 16th c. A type of harp associated with traditional music of Wales, originally a simple single-string instrument and now more usually referring to a type of triple harp.
Etymology from Wiktionary, CC BY-SA 4.0.