conversion

American  

[kuhn-vur-zhuhn, -shuhn] / kənˈvɜr ʒən, -ʃən /

noun

1. the act or process of converting; state of being converted.

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

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

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

5. 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.

6. a physical transformation from one material or state to another.

   conversion of coal, water, and air into nylon.

7. the act of obtaining equivalent value, as of money or units of measurement, in an exchange or calculation.

   conversion of yen into dollars.

8. 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.

9. a substitution of one component for another so as to effect a change.

   conversion from oil heat to gas heat.

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

11. 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.”

12. Law.

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

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

13. 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.

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

15. Physics. the production of radioactive material in a process in which one nuclear fuel is converted into another by the capture of neutrons.

16. 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.

17. Computers.

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

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

    3. porting.

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

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

18. the transformation of material from a form suitable for printing by one process to a form suitable for another process.

    a halftone gravure conversion.

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conversion British  

/ kənˈvɜːʃən /

noun

1. 1. a change or adaptation in form, character, or function

   2. something changed in one of these respects

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

3. maths a change in the units or form of a number or expression

   the conversion of miles to kilometres involves multiplying by 1.61

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

5. law

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

   2. the changing of real property into personalty or personalty into realty

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

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

8. 1. an alteration to a car engine to improve its performance

   2. ( as modifier )

      a conversion kit

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

10. the unauthorized appropriation of a motor vehicle

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Other Word Forms

• conversional adjective
• conversionary adjective
• nonconversion noun
• preconversion noun
• semiconversion noun

Etymology

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”; converse ², -ion

Explanation

Something that is transformed from one state or form to another has had a conversion. The twentieth century saw the conversion from outhouses to indoor plumbing. You may oversee the conversion of your attic into an extra bedroom. The noun conversion can be used to describe some very specific transformations. If you exchange euros for dollars, you have made a monetary conversion. If your Canadian friend tells you, "It was warm today! It got up to 28!" and you figure out that 28 degrees in Celsius is the same as 82 degrees in Fahrenheit, then you have made a mathematical conversion. If you change your religion, you've had a religious conversion.

Example Sentences

Wales recycled well and it was Williams who deservedly crashed over under the posts to set up an easy conversion for Keira Bevan.

From BBC • Apr. 11, 2026

The researchers view it as an important step toward overcoming the constraints of current power conversion systems.

From Science Daily • Apr. 10, 2026

“It was quite simple. We saw the impact pretty immediately in terms of traffic to the site and conversion sales,” said Raissa Gerona, chief brand officer for Revolve.

From Los Angeles Times • Apr. 10, 2026

“If you have other pretax IRA money, part of the conversion becomes taxable,” says Sinnett.

From MarketWatch • Apr. 9, 2026

There would also be $281 million of "general conversion costs."

From "A Short History of Nearly Everything" by Bill Bryson

Related Words

• alteration
• changeover
• growth
• modification
• reconstruction
• reorganization
• switch
• transformation