Have a ball
Definition 1 of 1
Pro Tip 1/3Informal Context
Used in casual situations among friends, not for formal events or professional settings. 
You're going to have a ball on our road trip this weekend!
Pro Tip 2/3Positive Emotion
Expresses high levels of enjoyment and fun, more than just liking something. 
At the amusement park, we're definitely going to have a ball!
Pro Tip 3/3Suggests Activity
Implies active participation in what's happening, not just watching or being present. 
Join the dance competition; you'll have a ball!