Walking

(Other definitions for on foot that I've seen before include "where the corn's growing?" , "Walking or running" , "Going as pedestrian" , "By shanks's pony" .)

(Other definitions for hiking that I've seen before include "on a walk" , "On a trek" , "Raising" , "Rambling" , "Walking in the countryside" .)

(Other definitions for pacing that I've seen before include "Walking about, perhaps impatiently" , "Walking about, perhaps frustrated" .)

(Other definitions for on air that I've seen before include "In the process of broadcasting - floating aloft?" , "Walk in delight here" , "Broadcasting at this moment" , "(Walking) elatedly" , "Broadcasting studio sign" .)