Delicious is an adjective describing a tasty item. If you’re a chocolate fanatic, you will probably find triple chocolate fudge cake to be absolutely delicious.
The origins of delicious make perfect sense. The late Latin deliciae means "delight" or "pleasure," so you could say that delicious flavors and delicious foods give delight or pleasure to our taste buds. But let's not limit our pleasures to all things gastronomical. Things that delight your intellect can be delicious as well, especially when you're entertained by art, amused by wit, or delighted by irony. Thinking of the perfect comeback to an insult can be a particularly delicious experience.