Whether it's a boring class, an unappealing chore, or a dull event, if you're not looking forward to it and show little interest or happiness toward it, then you're unenthusiastic.
The word unenthusiastic describes a lack of excitement or interest. If someone’s unenthusiastic, they’re not really into what’s happening—like when you give a half-hearted cheer at a game because you don’t really care who wins. This word is often used when reactions feel flat or forced, as if the person would rather be doing something more fun. Being unenthusiastic means you’re not feeling the energy or passion, and it’s pretty clear you’re not enjoying whatever’s going on.