'low-wattage' is an English compound formed from 'low' + 'wattage'; 'low' comes from Old English 'hlēow' (meaning 'not high' or 'sheltered'), and 'wattage' derives from 'watt' (the unit named after engineer James Watt) + the suffix '-age' indicating an amount or related concept.

'wattage' arose in the 19th century from the unit name 'watt' plus the noun-forming suffix '-age' to mean 'amount in watts.' The compound 'low-wattage' developed later (20th century) in technical and everyday usage to describe devices or lighting that operate at a small number of watts.

Originally 'wattage' simply referred to the quantity of power in watts; over time the compound 'low-wattage' came to be used adjectivally to characterize devices as consuming little electrical power.