'smoking-reduction' is a Modern English compound formed from 'smoking' (the present participle of 'smoke') and 'reduction'. 'smoke' originates from Old English 'smoca' meaning 'smoke', and 'reduction' originates from Latin 'reductio', where 're-' meant 'back' and 'ducere' (via Latin) meant 'to lead'.

'smoke' came into English from Old English 'smoca'; 'reductio' passed into Old French and Middle English as 'reduction'; the two elements were combined in Modern English to form compounds like 'smoking reduction' (often written with or without a hyphen).

Individually, 'smoke' originally referred to the substance or action producing smoke, and 'reduction' originally carried the sense of 'leading back' or 'bringing down'; together the compound evolved to mean 'the act or measures of decreasing smoking'.