What does HALL stand for?

HALL stands for High Altitude Long Loiter

This definition appears very rarely

Other Resources: Acronym Finder has 3 verified definitions for HALL

Samples in periodicals archive:

Developmed by Aurora Flight Science and Boeing, the Orion, High Altitude, Long Loiter (HALL) Unmanned Aerial System is designed for stratospheric missions.

HALL (High Altitude, Long Loiter) program, Project Alpha's evaluation of these platforms and technologies; Geointelligence - High-Altitude Surveillance Page 3 of 4