General Science

  • verb to make something less, smaller or lower, or to become less, smaller or lower.
  • verb to add electrons or hydrogen to a substance


  • verb to lower the price of something


  • verb to convert raw data into a more compact form which can then be easily processed


  • verb to boil sauce so as to make it smaller in quantity and more concentrated

Information & Library Science

  • verb to make something smaller in amount

Media Studies

  • verb to lessen the density of a photographic negative or print using a chemical substance


  • verb to put something such as a dislocated or fractured bone, a displaced organ or part or a hernia back into its proper position so that it can heal

Origin & History of “reduce”

‘Lessen, diminish’ is a comparatively recent semantic development for reduce. Its Latin ancestor was certainly not used in that sense. this was redūcere, a compound verb formed from the prefix re- ‘back, again’ and dūcere ‘lead, bring’ (source of English duct, duke, educate, etc). It meant literally ‘bring back’, hence ‘restore’ and also ‘withdraw’. The original ‘bring back’ made the journey to English, and even survived into the early 17th century (‘reducing often to my memory the conceit of that Roman stoic’, Sir Henry Wotton, Elements of Architecture 1624). The sense ‘lessen, diminish’ seems to be the result of a semantic progression from ‘bring back to a particular condition’ via ‘bring back to order’ and ‘bring to subjection’.