'attenuation' originates from Latin, specifically the word 'attenuatio', where 'ad-' meant 'to/toward' and 'tenuare' (from 'tenuis') meant 'to make thin' or 'thin'.

'attenuation' changed from Late Latin 'attenuatio' into Medieval/Old French forms (e.g. 'attenuation' / 'attenuer' in French) and was borrowed into Middle English as 'attenuation', eventually becoming the modern English word 'attenuation'.

Initially it meant 'making thin' or 'rendering thin', but over time it broadened to the general sense of 'reduction in strength, intensity, amount, or severity' used in many technical and nontechnical contexts.