You are not allowed but if you want just hide it, the booze on board is very expensive.
Except for wine and champagne, alcoholic beverages may not be brought on board during embarkation or in ports of call. Bottles and other containers will be collected for safekeeping and delivered to your stateroom on the last day of the voyage. So the answer is No in common with nearly all the other cruise lines.
There have been occasional exceptions, certainly it appears from comments posted on this site that the much reviewed Ventura Christmas and New Year 2008/9 cruise allowed alcohol to be brought on board on embarkation. If true, this may not perhaps have been a great idea reading all the generally negative reports about this cruise and the apparently alcohol fuelled behaviour on board. It's a real shame, as I'm sure many people like me would like to take a bottle of spirit on board to have their favourite to hand for occasional cabin consumption.