Delectation is enjoyment, pleasure, or amusement — the feeling of being delighted. You almost never hear it as a bare noun in ordinary talk. The living use is the phrase for someone's delectation: you do the thing so that person can enjoy it. A cook might plate a pudding for the guests' delectation; a host might put on music for your delectation. The word is old and rather grand, so when people use it now it often has a small smile in it, as if they are playing at being formal. You would not say it when you mean everyday fun; you would say enjoyment, pleasure, or a good time. Though actually, that slightly theatrical tone is the point: it names pleasure as a gift laid on for someone.