Disposable stones or junk stones are stones that are strategically inessential, because they have no role in separating the opponent's weak groups. Stones played as kikashi having done some work already, often turn out to be disposable. The opposite of junk stones are important stones. The distinction is often made between junk stones and pivotal stones, cutting stones which play an important role in a contest between groups.
A proverb counsels us do not run away with junk stones.
Instead, White should play a big point like here.