A person who only wants pleasure.
A pleasure-seeking person who only seeks their own gratification.
A person who believes that seeking pleasure is the goal of life.
Hed - On - Ist
Heed Only My Interest
If you call someone a hedonist... it's usually considered negative.
You can say: I had so much fun... I was like a hedonist.
Then it only means... you had a good time... and it is not seen as negative... because it was temporary or short-lived.