[ kuhn-vur-zhuhn, -shuhn ]
See synonyms for conversion on
  1. the act or process of converting; state of being converted.

  2. a change in character, form, or function.

  1. a change from one religion, political belief, viewpoint, etc., to another.

  2. a thoroughgoing spiritual change that involves repentance and a turn toward God or right living.

  3. a change of attitude, emotion, or viewpoint from one of indifference, disbelief, or antagonism to one of acceptance, faith, or enthusiastic support, especially such a change in a person's religion.

  4. a physical transformation from one material or state to another: conversion of coal, water, and air into nylon.

  5. the act of obtaining equivalent value, as of money or units of measurement, in an exchange or calculation: conversion of yen into dollars.

  6. a physical, structural, or design change or transformation from one state or condition to another, especially to effect a change in function: conversion of a freighter into a passenger liner.

  7. a substitution of one component for another so as to effect a change: conversion from oil heat to gas heat.

  8. Mathematics. a change in the form or units of an expression.

  9. Logic. the transposition of the subject and predicate of a proposition, as “No good man is unhappy” becomes by conversion “No unhappy man is good.”

  10. Law.

    • unauthorized assumption and exercise of rights of ownership over personal property belonging to another.

    • a change from realty into personalty, or vice versa, as in the sale or purchase of land or the mining of coal.

  11. Football. a score made on a try for a point after touchdown by place-kicking or drop-kicking the ball over the bar between the goalposts or by completing a pass in or running the ball into the end zone.

  12. Psychoanalysis. the process by which a repressed psychic event, idea, feeling, memory, or impulse is represented by a bodily change or symptom.

  13. Physics. the production of radioactive material in a process in which one nuclear fuel is converted into another by the capture of neutrons.: Compare breeding (def. 6).

  14. Digital Technology. a performance metric for a website that counts the percentage of visitors that engage in the intended purpose of the site, as making a purchase or signing a petition: The site was redesigned to simplify user interactions and optimize conversion.

  15. Computers.

    • Also called data conversion . the act or process of transferring data from one format into another.

    • Also called media conversion . the act of transferring or copying stored data from one storage medium to another.

    • Also called system conversion . the change from an existing computer system to a new computer system.

    • the process of changing the base that a number or numbers are written in.

  16. the transformation of material from a form suitable for printing by one process to a form suitable for another process: a halftone gravure conversion.

Origin of conversion

First recorded in 1300–50; Middle English conversio(u)n from Anglo-French, from Latin conversiōn- (stem of conversiō ) “a turning around, revolution”; see converse2, -ion

Other words from conversion

  • con·ver·sion·al, con·ver·sion·ar·y [kuhn-vur-zhuh-ner-ee, -shuh-], /kənˈvɜr ʒəˌnɛr i, -ʃə-/, adjective
  • non·con·ver·sion, noun
  • pre·con·ver·sion, noun
  • sem·i·con·ver·sion, noun

Words Nearby conversion Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use conversion in a sentence

British Dictionary definitions for conversion


/ (kənˈvɜːʃən) /

    • a change or adaptation in form, character, or function

    • something changed in one of these respects

  1. a change to another attitude or belief, as in a change of religion

  1. maths a change in the units or form of a number or expression: the conversion of miles to kilometres involves multiplying by 1.61

  2. logic a form of inference by which one proposition is obtained as the converse of another proposition

  3. law

    • unauthorized dealing with or the assumption of rights of ownership to another's personal property

    • the changing of real property into personalty or personalty into realty

  4. rugby a score made after a try by kicking the ball over the crossbar from a place kick

  5. physics a change of fertile material to fissile material in a reactor

    • an alteration to a car engine to improve its performance

    • (as modifier): a conversion kit

  6. material alteration to the structure or fittings of a building undergoing a change in function or legal status

  7. NZ the unauthorized appropriation of a motor vehicle

Origin of conversion

C14: from Latin conversiō a turning around; see convert

Derived forms of conversion

  • conversional or conversionary, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012