There are several differences between conversion and larceny. While both are legal terms and used in relation to theft under criminal law, there are subtle differences between them. Conversion is also a broader term than larceny and is used in other fields such as religion, mathematics, logic and science.
The "Merriam-Webster Dictionary" defines conversion in several ways. Most frequent uses of the word are in describing "the operation of finding a converse in logic or mathematics" as well as the "experience associated with the definite and decisive adoption of a religion." Conversion is an act of change; for example a liquid can be converted into a gas, an atheist can be converted into a Christian, an imperial measurement can be converted into metric measurement.
A Legal Term
Conversion in law according to "The Encyclopedia Britannica" refers to the "unauthorized possession of personal property causing curtailment of the owner's possession or alteration of the property." The removal of property that is then changed into something else without the owner's knowledge or consent is regarded as conversion, regardless of the accused intentions. Examples would be cutting down trees from another person's land and converting them into lumber or taking a car for a joy ride and so curtailing the owner's use of it.
Larceny is synonymous with theft. It is defined by the "Merriam-Webster Dictionary" as "the unlawful taking of personal property with intent to deprive the rightful owner of it permanently." An example is taking a coat from a store and leaving or moving toward the exit with the intent of not paying. Immovable objects such as land or buildings do not qualify under larceny as they cannot physically change location.
Difference in Law
The difference between conversion and larceny as legal terms involves the state of the property and the intention behind the act. The property taken in larceny is not changed into something else and there is no intention of returning it. Property in conversion can change forms, though it can also refer to impending the owner's ability to use it such as a joy ride. To be regarded as conversion, the property has to be acquired without the owner's consent.