Efficiency of water resources is essential; just as important is the terminology that describes it. Paradoxes in terminologies used by various international institutions and professionals in the agricultural, urban and environmental domains are examined. Integrated terminologies are proposed, starting from flow-path types in water balance and expanded into the “macro, meso, and micro-efficiencies” (3ME) formulation. The 3ME is a systemic framework based on the principle of the conservation of mass, integrating water-flow paths of a water system, their beneficial and quality attributes (the usefulness criterion), climate, and two types of water totals. These terminologies, with nine examples for urban (three types) and agricultural areas (rainfed, surface, drip and sprinkler), are used to discuss the 3ME framework and possible flawed policy implications.