'water-efficient' originates from the combination of 'water' and 'efficient', where 'efficient' comes from Latin 'efficientem', meaning 'accomplishing' or 'producing'.

'Efficient' evolved from the Latin word 'efficientem' through Old French 'efficient', eventually becoming the modern English word 'efficient'.

Initially, 'efficient' meant 'producing an effect', but over time it evolved to mean 'achieving maximum productivity with minimum wasted effort or expense'.