Well, in Italian it means "Lucky" so the story is sort of ironic.
Fortunato is the one who dies.
The name Fortunato can mean fortunate one or simply fortunate. It is ironic because he is about to receive a most unfortunate surprise and meet a most unfortunate end once Montressor gets him down...
The meaning of the title is that cask is wine barrel, and the amontillado is a sort of dry wine.
Amontillado is a kind of sherry.