The story
Back-formation from Stonehenge, although it is not strictly a ME henge.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A prehistoric enclosure in the form of a circle or circular arc defined by a raised circular bank and a circular ditch usually running inside the bank, with one or more entrances leading into the enclosed open space. Full definition →
Back-formation from Stonehenge, although it is not strictly a ME henge.
Etymology from Wiktionary, CC BY-SA 4.0.