Meaning of “ballpark” - Learner’s Dictionary

ballpark

noun uk us /ˈbɔːlpɑːk/

[ C ] US a place where baseball (= game where teams hit a ball and run round four fixed points) is played and watched

ballpark estimate/figure

a number or amount that is not exact but should be near the correct number or amount:

$3 million would be a ballpark figure for sales next year.

(Definition of “ballpark” from the Cambridge Learner’s Dictionary © Cambridge University Press)