Dictionary.com
Thesaurus.com
Synonyms

conversion

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

noun

  • conversions
    plural
  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.


conversion British  
/ kənˈvɜːʃən /

noun

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

    2. something changed in one of these respects

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

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

    the conversion of miles to kilometres involves multiplying by 1.61

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

  4. 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

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

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

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

    2. ( as modifier )

      a conversion kit

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

  8. the unauthorized appropriation of a motor vehicle

"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

Other Word Forms

Derived Forms

Inflected Forms

Nouns

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”; see 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.

Keep Reading on Vocabulary.com

Vocabulary lists containing conversion

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The Gardens Trust, a parks and gardens heritage and conversion charity, called the decision to remove its role as a statutory consultee "devastating".

From BBC Aug. 16, 2026

If a Roth conversion is on the table, model it now, while there’s still time to change the answer.

From MarketWatch Aug. 14, 2026

Revenue quality at Plus500 is healthy, while high cash conversion supports further distributions, the analysts add.

From The Wall Street Journal Aug. 11, 2026

Potential applications include hydrogen production devices, other electrochemical energy conversion technologies, and oxygen separation systems.

From Science Daily Aug. 10, 2026

In fact, his public conversion to Islam in 1964 and his refusal to fight in the war thrust Ali into the spotlight for his beliefs as a Muslim, not his boxing.

From "Proud" by Ibtihaj Muhammad

So it actually makes sense to consider making Roth conversions while your taxable income is relatively low.

From MarketWatch Aug. 15, 2026

The key question is whether the tax you pay on those conversions now is lower than the marginal tax cost you are likely to face later.

From MarketWatch Aug. 15, 2026

Though none was deemed structurally hazardous, the department issued three construction violations at those conversions, including one partial stop-work order.

From The Wall Street Journal Aug. 4, 2026

Talk to a tax adviser about possible Roth conversions and ways to manage a potential tax cliff.

From MarketWatch Jul. 29, 2026

The engineers specified any conversions to be applied to the raw data—converting, for example, miles per hour to feet per second—and supplied Katherine with the equations to be used to analyze the converted data.

From "Hidden Figures" by Margot Lee Shetterly

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training