To stir or stir up is to produce concentrated movement, awakening, excitement, disturbance, urging, or agitation. The term can describe inner emotion, the rekindling of a flame, awakening from sleep, confusion, urging someone onward, or shaking something to and fro.
Scripture uses the expression for troubled or excited feeling, awakening, rekindling spiritual remembrance, confusion and tumult, urging others, and shaking them into movement. Its meaning depends on the Hebrew or Greek verb translated by the English expression.