(figuratively) To undertake a precarious course of action.

(historical, also figuratively) On an early naval vessel or pirate ship: to be forced to walk off the end of a gangplank (a plank of wood extending outwards from the side of the vessel) and plunge into the ocean and drown, used as a method of killing.

(idiomatic) To patrol on the job, especially as a police officer or guard.

To walk with no real planned destination, but to just walk, to meander "around".

(military) A patient whose injuries and/or illness are relatively minor, permitting the patient to walk and not require a litter.

An outdoor activity in which one follows the course of a stream (on foot, in the water), negotiating rapids and jumping or climbing waterfalls

Alternative spelling of gorge-walking

(plural only, in triage) Those casualties whose wounds do not require them to be moved on a stretcher but that can walk to medical treatment.

Any activity performed by an astronaut outside of a space vehicle in space.

(of an apartment etc) Reached by stairs rather than an elevator. / (of a block of apartments) Containing such flats. / (of a service) For which no appointment is necessary.