Hedonism is the belief that pleasure is the most important thing in life — that a good life is one with more pleasure and less pain. As a serious word, it names a way of thinking: some Greek thinkers argued this, and later writers still argue about it. That older idea was not only about parties; it was a claim about what “good” means. In everyday English, though actually, people use hedonism more loosely, and often with a little blame. “Pure hedonism” in a newspaper often means eating, drinking, shopping, and having fun with no thought for work, duty, or other people. That everyday use is harsher and smaller than the philosophy. The word is formal. You will meet it in essays and reviews, not in the playground. The person who lives this way is a hedonist; hedonism is the idea (or the habit), not the person.