A freshly minted bitcoin or one that has never been spent.
A virgin bitcoin is any bitcoin that has never been spent, is freshly minted, and therefore has no transactional history. These bitcoins are very rare considering that there is a fixed supply of bitcoins. Moreover, there is a wide conception that these bitcoins are more precious compared to others and should be priced differently. However, there is very little evidence that they exist, especially considering the number of years that the Bitcoin blockchain has been in operation.