The term "vinyl radical" typically refers to a type of chemical compound that contains a carbon atom with an unpaired electron, as well as a vinyl group (a carbon-carbon double bond). Synonyms for vinyl radical might include other terms used to describe this type of compound, such as vinyl carbene or vinylidene. Depending on the precise structure of the compound in question, it might also be called a vinyl free radical or vinyl cation. These terms are all closely related and can often be used interchangeably, depending on the context in which they are being used and the specific characteristics of the chemical compound in question.