(n) (1) A same general vicinity or idea as something else; an estimate of the scope and range of something.
(vb) (2) To estimate or approximate.
(1) He's looking for a used car in the $5000 ballpark.
(2) I'd ballpark Derek Jeter's life earnings to be about $200 million..
Thanks for the Eng lesson, I really appreciate it.
Promise you to practice it with my foreigner friends.