c. 1400, present-participle adjective from walk (v.). Walking sickness, one in which the sufferer is able to get about and is not bed-ridden, is from 1846. Walking wounded is recorded from 1917. Walking bass is attested from 1939 in jazz slang. Walking stick is recorded from 1570s; the insect so called from 1760, for resemblance of shape.
walking is a healthy form of exercise
walking distance
walk
walkabout
Walker
walkie-talkie
walk-in
walking
walk-on
walk-out
walk-over
walk-through
walk-up