Inflow/ˈɪnfləʊ/ Definition 1 of 2Pro Tip 1/3Physical Movement Inflow often denotes physical entry, like water entering a reservoir. The dam controls the inflow of water into the lake. Pro Tip 2/3Quantity Emphasis Emphasizes the quantity — usually substantial — when describing the movement. The inflow of donations after the broadcast was phenomenal. Pro Tip 3/3Not Always Positive 'Inflow' can indicate problems if what's incoming is undesirable. The city struggled with the inflow of pollutants into the river.