These words refer to the movement of fluids or a mass of particles. Flow indicates continuous and free movement, and often suggests slow, steady and untroubled passage: the broad river that flowed through my home town; the prevailing air current that flows from west to east; salt that gets damp and refuses to flow . Flow can have a lyrical tone: We watched the river as it flowed on under the bridge. By contrast, run is more matter-of-fact, although it is usually restricted to the movement of liquids. In this context, it is very general, suggesting any amount, channelled or unchannelled, moving in any direction: water running down the windscreen; In which direction does the river run ? In reference to streams or rivers, run may suggest faster movement than flow .

Pour most often suggests sharp downward movement: soot poured out over the city; water pouring over the dam. Stream can also apply to a movement both of fluids and of particles, but is otherwise like run in suggesting any amount moving in any direction. It usually suggests more rapid or more forceful movement, however: tears streaming down her face; smoke streaming from the chimney. As in the last example, movement in a narrow band or through a small aperture is often implied: water streaming through the irrigation ditches: cars streaming over the bridge.

Gush suggests surging, turbulent or sudden movement, whether in a general upwelling or a rapid jet: blood gushing from his head; water gushing in a fine spray from the fountains. Spout more strictly refers to a continuous or intermittent jet: waster spouting from the leaky pipe; Badly wounded, the whale began to spout blood.

Spurt can suggest small or intermittent jets: He squeezed the plunger of the hypodermic until the needle spurted out a few drops. Squirt , when distinct from spurt , may suggest a wider or more diffuse spray: water squirting from the fire hose. More commonly, the word is transitive: He squirted water at me.