And what means status "Replaceable"?
Seems you have enabled the "Replace-By-Fee" option in preferences? (or the person sending a transaction to you has)... this enables the transaction sender to resend the transaction with a higher fee if it gets "stuck" due to network congestion and a fee that is too low.
So, either:
A. If you sent it, letting you know that you can re-send the transaction with a higher fee if you find it has become "stuck".
or
B. If someone sent it to you... warning you, not to trust this transaction until it gets at least one confirmation, as there is a chance that it could be replaced (with the coins sent to another address) by the transaction sender.