unwilling
Not wanting to do something, even if you can.
Unwilling means not wanting to do something, or doing it only reluctantly or with resistance. When you're unwilling to clean your room, you don't want to do it and might drag your feet or come up with excuses to avoid it. When someone is an unwilling participant in a school play, they're on stage but wish they weren't.
Being unwilling is different from being unable. If you're unable to solve a math problem, you don't know how. If you're unwilling to solve it, you could do it but you don't want to. Maybe you're tired, or you think it's pointless, or you'd rather be outside playing.
Sometimes people are unwilling because they're scared or uncomfortable with something new. A kid might be unwilling to try sushi because it looks strange, even though they'd probably like it if they gave it a chance. Other times, being unwilling can show good judgment: someone might be unwilling to jump off a roof just because someone dared them to.
The word often appears in phrases like unwilling to compromise (refusing to meet halfway) or unwilling to admit a mistake (not wanting to say you were wrong, even when you know you were).