reduce

Etymology

From Middle English reducen, from Old French reduire, from Latin redūcō (“reduce”); from re- (“back”) + dūcō (“lead”). See duke, and compare with redoubt.

verb

1. (transitive) To bring down the size, quantity, quality, value or intensity of something; to diminish, to lower.
   to reduce weight, speed, heat, expenses, price, personnel etc.
   Becoming more aware of the progress that scientists have made on behavioral fronts can reduce the risk that other natural scientists will resort to mystical agential accounts when they exceed the limits of their own disciplinary training. 2012-01, Stephen Ledoux, “Behaviorism at 100”, in American Scientist, volume 100, number 1, page 60
   Most train operators have reduced services with emergency timetables, as they struggle to cope with a rapid increase in staff absences due to the Omicron variant of COVID. January 12 2022, Paul Clifton, “Network News: Emergency timetables as absences surge due to COVID”, in RAIL, number 948, page 6
2. (intransitive) To lose weight.
3. (transitive) To bring to an inferior rank; to degrade, to demote.
   to reduce a sergeant to the ranks
4. (transitive) To humble; to conquer; to subdue; to capture.
   to reduce a province or a fort
5. (transitive) To bring to an inferior state or condition.
   to reduce a city to ashes
6. (transitive, cooking) To decrease the liquid content of food by boiling much of its water off.
   Serve the oxtails with mustard or a sauce made by reducing the soup, if any is left, to a slightly thick sauce. 2011, Edward Behr, James MacGuire, The Art of Eating Cookbook: Essential Recipes from the First 25 Years.
7. (transitive, chemistry) To add electrons / hydrogen or to remove oxygen.
   Formaldehyde can be reduced to form methanol.
8. (transitive, metallurgy) To produce metal from ore by removing nonmetallic elements in a smelter.
9. (transitive, mathematics) To simplify an equation or formula without changing its value.
10. (transitive, computer science) To express the solution of a problem in terms of another (known) algorithm.
11. (transitive, logic) To convert a syllogism to a clearer or simpler form.
12. (transitive, law) To convert to written form. (Usage note: this verb almost always appears as "reduce to writing".)
    It is important that all business contracts be reduced to writing.
13. (transitive, medicine) To perform a reduction; to restore a fracture or dislocation to the correct alignment.
14. (transitive, military) To reform a line or column from (a square).
15. (transitive, military) To strike off the payroll.
16. (transitive, Scotland, law) To annul by legal means.
17. (transitive, obsolete) To translate (a book, document, etc.).
    a book reduced into English