Because it has been dismissed, it was never sent to the other account. We can see it as a refund … But I think that there’s a word which represents more the concept.
By the blockchain point of view, an account exchanges the XEM (for example) when a transaction is included in a block. When a transaction is unconfirmed, the amount is still in the origin account, and it’s not until the transaction is confirmed that the amount is successfully transferred.
I don’t know if I’ve explained well, but I hope that you catch the idea