Transient means a state or situation which changes quickly, or a person moving from place to place without settling in one place.
These paragliders seen on Mount Pilatus Switzerland represent transient to me as they must experience a short period of extreme adrenaline and excitement while practicing their sport
He draws on the sidewalk everyday earning a little bit of money from passersby. His art however is not permanent it can be washed away by rain or damaged by people walking over it. Photo taken in Siena Italy