My first is twice in apple but not once in tart; my second is in liver but not in heart; my third is in giant and also in ghost; whole I'm best when I am roast. What am I?
I come once a year, a day of cheer, A time to laugh and not to fear.
My jokes are many, and some are bad, But they're all in fun, so don't be sad.
I'm not a holiday, nor a festivity, Yet I'm celebrated with much levity.
What am I?
