Hosp. test

EEG

This brainwave-monitoring procedure often involves placing electrodes on the scalp to record electrical activity.

"Hosp. test" is short for a hospital test, and "EEG" stands for electroencephalogram, a common medical procedure that records brain activity. The clue uses an abbreviation ("Hosp.") to hint at another abbreviation ("EEG"), which is a standard shorthand in medical contexts. It’s a straightforward definition clue with no wordplay—just a direct reference to a well-known diagnostic tool.